Look, you may have interest in Software, Analytics or Finance but that doesnt imply not giving attention to your current Mechanical curriculum. Firstly you should keep up with your Course Curriculum and Tests and ensure you  maintain a CGPA above 8, before you venture and start working on your own interests.

Now coming to the Software Part, most of the NITs entertain wide number of Software and Finance Companies during Placements and Internships. You need to first master the Three main Programming Languages namely C/C++/Python followed by regular practice of Competitive Programming on platforms like HackerRank or CodeForces. Besides this you also need to develop skills in Machine Learning, Artificial Intelligence as well as Data Analytics, which are equally critical for a career in Tech Fields followed by a Couple of Internships in Software Development/Machine Learning/Data Analytics. In todays date lot of Virtual Resources are available for aceing in any area like Courses from Udemy, Coursera and EDx as well as Virtual Internships amd Trainings from Providers like Forage and InsideSherpa.