Hello Harsh, 

Nirma University provides chemical engineering under 2 courses :

1. B.Tech

2. PHD

I'm afraid they do not have a diploma course for this. For applying to B.Tech in this university you need to pass your 12 boards with a minimum of 45% in maths and physics. And then apply for the JEE Mains and then GUJ-CET. Other details regarding their chemical engineering course can be found here  :   https://www.careers360.com/university/nirma-university-ahmedabad/btech-chemical-engineering-course

Hope this helps  :)