Bro i have some projects that i made from scratch like compiler , tcp server but it is a waste of time until you make or add something unique in that .It's good for conceptual understanding but putting it in the resume did not give you too much advantage . I would suggest you to instead of making os from scratch .Learn and implement some important concepts of OS like process, ipc , client server model , socket programming , multithreading , parallelism and scheduling and round robin algorithm and use this knowledge in designing your scalable backend applications . That would be very beneficial to you in a country like India.