IES's Management College and Research Centre

Hello Saumya,
Firstly, you have a strong chance to get admission in this college since marks are very good. You can surely apply either to PGDM or MMS program.

Yes, you can in fact clear IES Mains exam with CSE branch but you have to focus on another branch's subjects and clear the IES exam.

https://upsc.gov.in/sites/default/files/Notice-ESEP-2020-Engl.pdf
Go through this important website to know more about your problems.

Just go through this link and fill out the required details:
https://www.shiksha.com/college-predictor

https://www.onlineengineersacademy.org/ese/
another one is byju's you can join classes.

You should check the college website or contact them in person. They will be able to give you the most authentic and accurate knowledge for the percentile cut offs keep changing very often. Good luck.

As per UPSC, any government official applying for IES/ ESE will get the age relaxation even if he/she is already working on a post which is considered of a higher officer cadre. There is an age relaxation for the ones who have worked with any government organisation on contractual basis for a period of 3 years or more.