Puma has good options i.e both in style and comfort for gym wear.
You can check out HRX (By Hrithik Roshan)! It's available online on Myntra. And ofcourse then you have the go-to options like Addidas & Reebok!
You can also checkout jockey and nike the same
Decathlon has great quality and pocket friendly gym wear collection
You can try H&M , Decathlon , Uniqlo , Lurv.com and Clovia are some of the places where you will surely find something that will fit your style.
AJIO, ShoppersStop . You can find a lot of variety stuff . Also they are fashionable as well
Decathlon has good quality products not sure about reasonable though.