If you don't want to go for Amazon and Flipkart but still want to buy online:-
1. Wooden Street.com/wall-frames
Both the websites have resumed their delivery service and have a lot of variety compared to Amazon or Flipkart
Kabari market Amar Colony behind Lady Shriram College.
You might find this at The Wishing Chaur. They have some really quirky stuff
You can check printstop and chumbak
Banjara Market. Or you can even get it customised by your carpenter- it won't burn your pockets and you'll get the design of your choice.