Hey.

Yes, Chemical Engineers do have a great scope in ISRO after completing their Mtech. Given below are two links first one gives you an insight regarding how to work with organisations like ISRO, DRDO etc. The second list is a list of vacant posts in ISRO for Chemical engineers and others with eligibility and selection procedure.

https://www.google.co.in/amp/s/engineering.careers360.com/articles/isro-drdo-barc-dae-how-work-here%3famp

https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.isro.gov.in/sites/default/files/adv_01_english_final_2.pdf&ved=2ahUKEwiV56iIncLcAhXMtY8KHSDyAtsQFjACegQIABAB&usg=AOvVaw1uMVqyLh91POLPCIc9pZb9