Hello 

As from this year your percentile score will decide your rank. And admission will be based on only your rank.

And cut off vary from branch to branch with category.

You should secure rank under 8-10 thousand ( vary depending upon your category and state) for a core branch and for this you have to score atleast 99.2 + percentile marks.

You can see last year's cut offs ( closing ranks ) and take it as reference using this link:

https://engineering.careers360.com/articles/jee-main-cutoff-for-nit-calicut/amp

So good luck