I have coached an indian junior player, so I am probably qualified to answer here.
if you started at 13, then there is no ways you can make the indian national team. the indian team is very strong.
try changing nationalities to a weaker table tennis country.
if you stay in india, what must you do?
1) join a table tennis academy, there are hundreds if not thousands of them. You should know where to look or who to ask. If you don't know, then you not in the professional group.
2) once you join, see if you can actually get in. If you are not strong enough, they probably won't want you. Here they train 6 to 7 hours a day, 6 days a week.
3) once you can cope with 2, now know, if you not top 1 or 2 in the academy in your age group, you will struggle, because there are hundreds to thousands of academy in across india. how do you know if you are good? represent your club to play state tournaments
4) then if you are good in state tournaments, you will represent your state to play national tournaments
5) and only then, you might have a spot low down the indian junior team, and you need to work your way up.
You probably need to move to China, Japan or Taiwan and train fully time to try and catch up.
But the odds are low, because Indian level is very high.