india – Now that NGT has banned private vehicles from entering the Rohtang pass, what route should I take?

Is it clear for sure that tourists who are headed for Ladakh won’t be
blocked from entering the Rohtang pass? If so, how would the
authorities confirm that the tourist is headed for Ladakh?

There is no way to stop this from what I know. What about those who really plan to go to Ladakh but 100kms into the journey they get a phone call from home about some urgent situation that needs them to return immediately? Government cannot do much on that route except for charging every one and not just those who visit Rohtang pass alone.

If you suggest against taking this route, can you suggest the
alternative route, like Delhi-Srinagar-Leh route, and the current
situation thereof?

Have a look at the differences and see which one you like and decide Srinagar Leh route vs Manali Leh route.

Delhi Srinagar Leh roads are in a lot better condition as compared to Manali Leh road simply because Srinagar route is used by the armed forces on a daily basis and is used to transport defense equipment and other supplies every day where as Manali road is mainly used by tourists and locals. I have been to Leh both ways and find that Manali route is more scenic and I did not find much traffic on that route where as Srinagar route is normally busy.