If you apply thru CK for the new BPCL , then it will most likely be rejected because of "Over leverage" issue ( 90%) chance..
But if you are approved for the new card, then it will have a new seperate limit on top of your current 1.2L limit on the other card..
It all depends upon your overleverage situation in the eyes of SBI..
So other things being equal and you are not considered as Over leveraged by SBI then you will get new limit otherwise rejection ..
All the best