Aditya, 

There's basically no official announcement of cut off at NEHU Shillong official website. 

But seeing the trends at other websites and gathering information from people who have studied there i can give you some information. 

I think any score around 90-100 will definitely fetch you the seat in NEHU Shillong whether let it be IT branch or ECE branch. 

If you get marks around 100 you will definitely get a seat. 

I hope this helps!!  I will further check about this college and of possible I will provide you with exact information.