Possible career path for a pure math student
I'm glad that you're interested in further study. I'm actually not familiar with the Indian job market right now, but if you're not interested in academia, then in that case, here is what I would recommend:

Get a PhD in CS or Business (Computer Information Systems) - go to Data Science is a great career, even if you don't enjoy it that much, it is very lucrative as you said, and it is also pretty interesting. Information Security is a booming field, and is huge right now. You can also do this through pure mathematics, by getting your PhD in Math and specializing in computational number theory, while staying involved in InfoSec work (through internship, for example). 

The academic job market in India, especially for Professors, seems to be relativity good at the moment, so it may be easy to get a job as one. I don't know this for sure though. It seems like this isn't an option for you though, so here is what I would say: 

Do something like I suggested above (I strongly believe that Data Science is the way to go), and try to get into a reputable institition in India (if you plan to stay there), like IIT. Otherwise, there a lot of good institions throughout the world that you can look into. To become a data scientist, you need to apply to PhD programs in CIS/Business/CS, and join a research group that has a Data analytics concentration (talking in regards to my experience here in the USA). There's a lot of US Companies that have major offices in India, and Data is a big field now that is under-saturated currently.