Hello Sumit

As you know the cutoff's are still not released yet and it will only be released after the conclusion of April exam.

You can calculate the predicted rank using the below formula but you cannot calculate the score using the percentile.

((100-percentile)*875000)/100

Here is the link which can be helpful for you : https://engineering.careers360.com/articles/jee-main-cutoff

If you go with the recent trends and considering the previous year's cutoff then it will be quite difficult for you to get MNIT (CS), yes you may get a good branchesbut i am not sure about CS in MNIT( approximation).