The reason Indian students collaborate so much is because the way Indian education system works, hustling students survive better. Students who can read, share and gather information with peers always tend to do better than lone geniuses.
Also, the population ensures that there aren't enough resources for everyone. So, everyone learns to share. A lab project? Share!! You want to do a survey? Form a group and do it. Want computing resources? Share it with others in that time slot. Participating in competitions? All of them are team based competitions.
This is a cultural difference. Nothing else. Also, it's not like all the Indian kids are homogeneously helping each other. They all have their own cliques and many students don't want to share their solutions with other students (Indian or not). Many want to find a better solution.
The solution is simple (something the CS reps in my school implemented with great success). Make homework and (some) tests incredibly hard and encourage team work.
Some of the programming projects we had were so complex that the class had shared forums where we would solve problems right under the nose of the TAs and the prof with full visibility. So, while the code would be individually written, problem solving in the abstract can be a team effort.
An example of how to make them harder would be to deliberately introduce bugs in a codebase that you deployed for a homework. This teaches them how to find solutions and debug.
Sure, some students will chill until the last moment and try to gather answers from friends. But, most students who worked their ass off would never share their solutions (mostly to get themselves up the bell curve). A lot of students will try to make their solutions better by improving on the shared common answer but never revealing it to anyone but the grader.
For exams, we had open book, open laptop, full internet access tests. In those tests, all students would log into chat box to discuss answers. But the questions were tricky and needed speed to solve. So, being on the chat just made sure students are wasting time. The only people who could finish those tests were students who knew what they were doing.
I know this is not ideal in the US. But its a strategy (if used sparingly) that works really well. To be honest, it makes students be super prepared and study real hard so that they can complete tests faster, yet know that they can rely on their friends to get them some info if they happen to forget it.