Dear Srirag,
For careers in Robotics, Sometimes you need to be an expert in Electronics, Sometimes in Mechanical engineering, Sometime in computer science and sometimes in communication. Right now, you must widen your knowledge in these subjects. So start your B. Tech in any of the above said fields. Focus your aim to Robotics and do projects related to it. After completing your B.Tech, It is time for you to specialize in Robotics. You may go for Masters or Join for PhD. programs available worldwide. Then finally to a fascinating career in Robotics. In nutshell- Join B.Tech-then Specialize.