Hello there,

Yee, you can always pursue M.SC Chemistry after you have completed your B.Tech in Chemical Engg. For that you need to sit for the Joint Admission Test(JAM) Conducted by IITs which is also known as IIT-JAM. With this examination you can pursue your career in MSc. In various IITs/NITs/GFTIs/Renowned institutes.

Follow this link to know more about the examination of IIT-JAM

https://university.careers360.com/articles/jam

Cheers!