In India, you have to go through security again for domestic transfers.. Exception - If you are on a single ticket and the transfer time left is less than 40 mins, then in some cases airline arranges for aircraft door to aircraft door transfers (i've had this in DEL with 9W for SXR-DEL-BLR flight on multiple occasions)

Few things to note:
- Larger airports (DEL/BOM/BLR) have multiple terminals physically separated which may involve a land side bus/taxi ride - additional time to be kept for same if different tickets
- Most larger airports (DEL/BOM/BLR) have a small transfer security area before baggage claim if your flight is leaving same terminal that lets you avoid joining general crowd security..