Hi.

Can you rephrase your question? I dont know what exactly you meant by "PCB 136"

I can only assume that you mean that you have got 136/300 in PCB that means you have got 45.3% which makes you unqualified to be able to write NEET Exam.
However, for NEET you need minimum 50% in PCB for that you can give Improvement CBSE Exam.

If you have applied for the improvement exam then you will be allowed to take the NEET Exam but you will not be allowed to take admission until and unless you improve and earn higher than 50% marks in PCB Category.

If you have a further specific query please feel free to comment.

Best of Luck.