There is a clear phased approach recommended across coaching platforms:

Phase 1 — Sectional / Subject-Wise Tests (from Month 3 onward): As soon as you complete a subject or a major topic, start solving sectional tests on it. Do not wait until you have covered the entire syllabus. Early sectional tests identify gaps while there is still time to address them.

Phase 2 — Full-Length Prelims Mocks (4 to 6 months before exam): Begin full-length 100-question GS Paper I mocks once you have covered at least 60 to 70 percent of the static syllabus.

How many mocks: The consensus target is 25 to 40 good-quality full-length mocks, plus 10 years of PYQs solved at least twice. Quality of analysis matters more than quantity — solving a mock without detailed error analysis is half the benefit.

Mock analysis protocol: For every mock, spend at least as much time on analysis as you spent taking the test. Categorise wrong answers into: conceptual gap, elimination error, silly mistake, and knowledge gap. Each category has a different fix.

CSAT: Do not neglect Paper II (CSAT). It is qualifying (33% = 66 marks out of 200), but candidates with weak comprehension or arithmetic skills have failed Prelims despite strong GS scores. Take at least 10 to 15 full CSAT mocks.

The most common first-attempt error: starting mocks only 6 to 8 weeks before Prelims because 'preparation is not complete.' No preparation will ever feel complete — start mocks when about half the syllabus is done.