A friend of mine recommended me CIT as it is the oldest and a government-aided research institute. CIT was started much earlier than SSN. Needless to say, the institute has much more facilities to offer you as it is the most trusted. 

Here are some basic information about the three institutes:

• If you ask about computer science, SSN and CIT are on the same page. Both the institutes are equally great. If compared on the basis of the CS department, VIT is lagging behind as compared to SSN and CIT. 

• CIT and SSN are more affordable as compared to VIT as it is a deemed University. 

• SSN has the best infrastructure among the three universities. 

• In order to encourage research, SSN offers an amount of twenty-five thousand rupees as part of internally funded projects. You can collaborate with top institutes like Anna University or IIT for projects.

• Though the faculty and quality of teaching at VIT lags behind, it is not the case in CIT and SSN. Both the institutes have a very strong faculty being top institutes.

• If you are planning to study abroad in the near future, SSN should be your ultimate destination. It is known for providing students with facilities to study all around the nation and the world. 

Though the oldest and the most affordable institute among the three is CIT, if your budget allows, you must go for SSN. It is also located in a metropolitan city. You can keep VIT as a backup option due to issues like affordability, comparatively poor faculty, and lack of enough research facilities.