IFLYI
If the F-PLAN represents the route you will fly, includes the arrival and approach - if the CRZ FL is correct, the winds and OAT are entered - then the EFOB at destination will be pretty accurate.
If that is less than required by your Company or Indian regulations, then you have to make a decision. No amount of technical fiddling will help you, all it takes is the courage to actually make that decision.
Regards
TP