IIM

Before we dive right into what one needs to focus on, let us first understand FMS's selection criteria -
1. Weighted CAT 2021 Score - 50%
2. Marks obtained in Class X - 10% (60% and above but less than 75%: 5%, 75% and above: 10%)
3. Marks obtained in Class XII - 10% (60% and above but less than 75%: 5%, 75%, and above 10%)
4. Discussion on Statement of Purpose - 10%
5. Extempore 5%
6. Personal Interview - 15%
Point number 2 and 3 above are things that you cannot control, so let us focus on point 1 which is most essential, i.e your CAT score. Because only after a good CAT score (99.3+ for General Engineering Male) you will get an interview call and point 4,5 and 6 will become relevant.
So the strategy to target FMS is no different than the strategy to target top IIMs, based on historical data you need to aim to score 99.3+ percentile in CAT.