If u r providing online food delivery through an e commerce operator then mandatory registration if u provide it through ur own app or website then 20lakhs limit
Note : If your supplying on behalf of any E-commerce , who is deducting TCS then as per section 24 of CGST Act you are mandatory require to obtain Registration , even though your turnover is below threshold limit as prescribed in section 22
If you are providing it with the help of Food Delivery Apps like Zomato, Swiggy etc, then GST Registration is MANDATORY by virtue of Section 24 of the CGST Act 2017.
But if you are providing the food through your own application ( online food delivery app ), then the limit will be Rs. 20 lakhs in accordance with the Provision of Section 22 of the CGST Act 2017.