hi,

see to become a scientist you need to complete your post graduation and may aslo need to do phd , however research organizations like isro, drdo have recruitment comes for msc chemistry degree holders. to pursue msc in chemistry in india iits are best because of innovative curriculum, lab technology, excellent professors. to get admission in iits you need to appear in iit jam entrance test, while you are in your final year of graduation you may apply for iit jam exam. to know more details of iit jam follow the below link,

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