Yes, you can pursue an MS in Computer Science from abroad even with a BTech in Mechanical Engineering from India. While a CS undergrad is ideal, universities value well-rounded students with strong analytical and problem-solving skills, which mechanical engineering cultivates. Highlight any CS or programming courses you took during your BTech. If your background is light, consider taking online courses or MOOCs (Massive Open Online Courses) in CS fundamentals to demonstrate your interest and ability.

Some universities offer MS in CS programs with bridges or preparatory courses for students from non-CS backgrounds. Look for programs that acknowledge the value of your engineering background while providing a foundation in CS.

I hope it helps!