KC in Lajpat Nagar is a good bet
Lajpat Nagar Market is open now and you'll find some reasonable good quality fabric there.
There are plenty of fabric shops in Lajpat Nagar where you can shop for a wide range of fabrics at affordable prices!
Why don’t you check out Fabriclore.com they have a large variety of materials. I am sure you will find something that you can use for your dress. I would not suggest you to go out at this point of time to outsource fabric so Fabriclore is the best option according to me. Stay safe.
Chandini chowk is the market full of fabrics
Saste Kapde Ka Depot Rk Puram. If you want reasonable things with good quality. Give them a try!!
Shankar Market , Connaught Place . It is a good market.
You will also find some amazing options at Ramji And Sons in Lajpat Nagar!