[kotakota]

Personally I would recommend doing a ms if you can afford it but if you can't I would recommend that you study the following areas Algorithms and data structures (this is a must) Systems organizations and architecture Systems programming Discrete math Math for cs books (generally proof based descrete and calculus based) Statistics and probability Then Start diving into areas that interest you like Metaheuristics Ai Machine learning Computer vision Compilers Device drivers Graph theory Computer Graphics (if your working in theoretical computer graphics strong maths skills are recommended) And the list goes on. Also read papers were in areas of interest. Papers are a great way to learn high level theoretical concepts.