Swiggy instamart has 100 off on 400 for new users (HELLOIM). Combine with discounted gv from fave.
Blinkit has 100 off on 299 in selected cities.
More supermarket recently launched their app, it gives 25% off upto 100 on first order.
I know only about these since other apps not available here, jiomart doesn't have any new user offer.