Hey Swarnendu

The cutoff for IISER via IAT for general category  is around 100 to 105 but the cutoff may vary. Sometimes in the last rounds (depending on luck) the cutoff can go down to 80 (rare occasion but possible).  However no official statement is released as to the cutoff from IISER, you will only be told if you are selected or not. My only advice to you is not to loose hope and stay in the game till the end.