@sushant did'nt get your point ? "after starting with 'b', we cant decide wehther we should start popping 'a' or push 'b' "
after starting with 'b' => If i start with b then only possiblity for acceptance is {bncp | n = p}
we cant decide wehther we should start popping 'a' => If i start from b then after it a cannot come if it comes i'll add transition to dead state.
Non determinism comes here when i/p starts from 'a' now i cannot say whether i should push a's to compare with b further OR i should ignore a's nd push b's to compare with c's.