How much cost will be charged at the time of delivery to india including all taxes and service charges?

No shipping to India due to high theft rate

Is the crystal scratch resistant?

Mineral glass will be scratched over time. Replacing it with sapphire on this model is not easy as far as I know. Long Island was offering that mod but stopped because the commonly available sapphire will interfere with the hands on this watch. I have had a scratch on my Orient mineral crystal which is deep enough to annoy me. I successfully buffed it out with diamond power polishing paste (use 5, 3, 1um size). Total cost was $15.

Why is the date not changing? Any solutions

The crown of the watch can be pulled two times, one for date and next for time. So, pull the crown gently and rotate the crown in clockwise direction.

Is t screw down crown and hacking?

Not a screw down crown, yes it can be hacked. This is not a hand winding movement. The Orient Cal. 48743 Automatic Mov’t only winds through the motion of the watch.