You can buy from a few places, most likely not eBay properties as has been suggested by other comments.
The most popular is probably Alibaba - or AliExpress - the latter being for smaller quantities and is generally a bit safer. This is typically for buying from wholesalers or manufacturers in China (only buy from verified members - these have been verified by Alibaba, otherwise you could get cheated).
If you want to keep things domestic, then try out IndiaMart, which is generally for Indian wholesalers (who may have bought or manufactured domestically or more likely imported stuff from China).
Alternatively, you can go to markets in your local town, or if you're after something specific (maybe jewellery?) you can go to Jaipur and do a bit of haggling!
If you want to get in to more high end stuff, maybe mobiles that aren't available in India, you can do back to back inventory and purchase from abroad (maybe the US/ UK) when you receive an order - you just have to make sure that your lead times advertised as being longer than most.
Or, you could sell Indian items abroad!
Hope that's of use, and good luck 🙂
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