NTTF already equips you with the technical expertise to be industry-ready and employable with its diploma program. So you don’t need to go for higher studies. If however you still want to do a post-diploma, then you can do that from various institutes such as Indo German Tool Room (IGTR) - Aurangabad.
However, I would still say that getting experience in the field working with companies is a much better way to achieving your goals rather than studying more.