Thanks.
I thought KGP, instead of BBS would be better for change-over, when i saw lot of slack time for 12864 between BBS and KGP and also, 12801 halts @ KGP for good 25 minutes for loco reversal.
So, even if 12801 reaches KGP first and 12864 reaches 20 minutes later, still we can make it. I had taken that risk and booked a ticket for KGP-BKSC journey for my colleague and have to book a CK ticket in 12864 tomorrow.