Hello Ratan,

  Answer to your question totally depends on your own interests. If you are more interested in research and thinking of doing Phd or MS then I will suggest you to join IISER, but if you are more interested in industry or corporate jobs then NIT Trichy is much better option. So, its upto you to decide between research and high paid jobs. If you are really passionate about the research then you must join IISER and if you are not much clear about what to do in future and research is not one of your interest then joining NIT is the best option..

 Good Luck !!!