Hi

First of all admission in IITs is through JEE advanced examination and in jee advanced there is nothing like percentile , rather you have rank.

Also,

IIT Guwahati doesn't offer integrated MSc physics ,you can check the same by visiting its official website for which link is provided below

https://www.iitg.ac.in/acad/courses_syllabee.php

You can check closing rank for all the branches in IITs, by visiting official website of Josaa for which link is provided below

https://josaa.nic.in/Result/Result/currentorcr.aspx

To have a personalised report on your chances of getting a college you can go through our college predictor, it will give you complete list of colleges which you can get on the basis of the category you belong to,  your home state, your gender etc, the link for  jee main college predictor is provided below

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

Jee advanced college predictor :-

If you have any other doubt then you can always reach us to clear them :) we are always available to help you out and guide you

Thank you