How to Become a Sub Inspector (SI): SSC CPO, State Police, CAPF — All Routes, Eligibility and Selection
Complete guide to becoming a Sub Inspector — SSC CPO for Delhi Police and CAPF, state police SI exams (UP, Bihar, Rajasthan, MP), eligibility, physical standards, exam pattern, salary comparison, and career growth path from SI to SP.
Sub Inspector is the most popular entry-level officer rank in Indian policing. Unlike a constable, an SI is a gazetted officer in many states, carries investigation powers, and can file chargesheets. Lakhs of graduates attempt SI exams every year — but there are multiple routes, and picking the right one can save you years of preparation.
Here's every path to becoming an SI, with real eligibility details, physical standards, and salary numbers.
What Does a Sub Inspector Do?
An SI is the first investigating officer rank in Indian police. Key responsibilities include:
- Registering FIRs and investigating criminal cases
- Leading a police station in the absence of the SHO (Station House Officer)
- Filing chargesheets in court
- Maintaining law and order in assigned areas
- Supervising constables and head constables
Routes to Become a Sub Inspector
There are three main entry paths — each with different exams, eligibility, and career trajectories.
| Route | Exam/Authority | Posts | Best For |
|---|---|---|---|
| SSC CPO | Staff Selection Commission | Delhi Police SI, CAPF SI (BSF, CRPF, CISF, ITBP, SSB) | Central government posting, Delhi posting |
| State Police SI | State-level commissions (UPPBPB, BPSSC, RPSC, MPPEB) | State Police Sub Inspector | Home state posting, state cadre |
| UPSC CAPF (AC) | UPSC | Assistant Commandant (higher than SI) | Higher rank, all-India service in paramilitary |
Route 1: SSC CPO — Delhi Police and CAPF SI
SSC CPO (Central Police Organisation) is the most popular national-level SI exam.
| Parameter | Requirement |
|---|---|
| Qualification | Bachelor's degree from recognized university |
| Age (General) | 20–25 years |
| Age (OBC) | 20–28 years |
| Age (SC/ST) | 20–30 years |
| Posts | SI in Delhi Police, SI in CAPF (BSF, CRPF, CISF, ITBP, SSB) |
- Paper I (Tier I): 200 questions — General Intelligence, General Knowledge, Quantitative Aptitude, English (200 marks, 2 hours)
- Physical Standard Test (PST): Height and chest measurement
- Physical Endurance Test (PET): 1.6 km race, long jump, high jump, shot put
- Paper II (Tier II): English Language and Comprehension (200 marks, 2 hours)
- Medical Examination
| Parameter | Male (General) | Female (General) |
|---|---|---|
| Height | 170 cm | 157 cm |
| Chest (unexpanded/expanded) | 80/85 cm | Not applicable |
| Race | 1.6 km in 6 min 30 sec | 1 km in 4 min |
Route 2: State Police SI Exams
Every major state conducts its own SI recruitment. Here's how the biggest ones compare:
| State Exam | Authority | Age Limit (General) | Qualification | Key Feature |
|---|---|---|---|---|
| UP SI | UP Police Recruitment Board | 21–28 | Graduate | Largest vacancies (often 5,000+) |
| Bihar SI | BPSSC (Bihar Police) | 20–25 | Graduate | Daroga exam — very competitive |
| Rajasthan SI | RPSC | 21–28 | Graduate | Includes platoon commander post |
| MP SI | MPPEB (Vyapam) | 21–28 | Graduate | CBT-based, physical test strict |
The written exam covers General Knowledge, Hindi, Maths, and Reasoning — though the exact syllabus varies by state.
Route 3: UPSC CAPF (AC) — Higher Entry
If you want to enter paramilitary forces at a rank higher than SI, the UPSC CAPF (Assistant Commandant) exam is the route. ACs are equivalent to DSP-rank officers and command companies of 100+ personnel.
| Parameter | Requirement |
|---|---|
| Qualification | Bachelor's degree |
| Age (General) | 20–25 years |
| Exam | UPSC CAPF AC — Paper I (GS) + Paper II (Essay/Comprehension) + Physical + Interview |
| Starting Rank | Assistant Commandant (equivalent to DSP) |
Salary Comparison Across Routes
| Post | Pay Level | Starting Salary (approx. gross) | Posting |
|---|---|---|---|
| Delhi Police SI (SSC CPO) | Level 6 | ₹44,000–₹50,000/month | Delhi NCR |
| CAPF SI (BSF/CRPF etc.) | Level 6 | ₹40,000–₹46,000/month | All-India (border/conflict areas) |
| UP SI | Level 4–6 (state pay) | ₹35,000–₹42,000/month | Uttar Pradesh |
| Bihar SI (Daroga) | Level 5–6 (state pay) | ₹32,000–₹38,000/month | Bihar |
| Rajasthan SI | Level 5–6 (state pay) | ₹35,000–₹40,000/month | Rajasthan |
| CAPF AC (UPSC) | Level 8 | ₹58,000–₹65,000/month | All-India |
Physical Standards: State-Wise Comparison (Male, General)
| State/Exam | Height | Chest (Unexp/Exp) | Race |
|---|---|---|---|
| SSC CPO | 170 cm | 80/85 cm | 1.6 km in 6:30 |
| UP SI | 168 cm | 79/84 cm | 4.8 km in 28 min |
| Bihar SI | 165 cm | 81/86 cm | 1.6 km in 6:30 |
| Rajasthan SI | 168 cm | 79/84 cm | 5 km in 25 min |
| MP SI | 167 cm | 79/84 cm | 800m race (timed) |
Career Growth: SI to SP
The promotion ladder from Sub Inspector upwards:
- Sub Inspector (SI) — starting rank
- Inspector — after 8–12 years
- DSP (Deputy SP) — departmental promotion after 15–20 years (or directly via State PCS/UPSC)
- SP (Superintendent of Police) — rare through promotion, mostly IPS officers
If you enter through UPSC CAPF AC, you start at DSP-equivalent rank and can reach IG level.
Which Route Is Easiest to Crack?
Honestly, none of them are "easy" — but here's a practical comparison:
| Factor | SSC CPO | State SI | UPSC CAPF AC |
|---|---|---|---|
| Competition | Very high (20–30 lakh applicants) | High (varies by state) | Moderate (2–3 lakh applicants) |
| Syllabus Difficulty | Moderate (SSC-level) | Moderate (state-level GK heavy) | High (UPSC-level) |
| Physical Test | Strict | Varies (some states stricter) | Strict |
| Preparation Time | 6–12 months | 6–10 months | 10–14 months |
| Starting Salary | Highest for SI level | Moderate | Much higher (AC rank) |
Preparation Strategy
- Start with physical fitness — begin running and exercises 3–4 months before the physical test dates
- Maths and Reasoning — common across SSC CPO and state exams, practice daily
- General Knowledge — focus on current affairs (last 6 months), Indian polity, and history
- English — important for SSC CPO Tier II, practice comprehension and grammar
- Previous year papers — solve at least 5 years of papers for your target exam