Composition scheme

Since a composition dealer does not charge GST under the specified rates, but has to pay GST at flat rate, he will not be able to issue a tax invoice to you.

Instead, he will issue you a bill of supply.

As a result, you will not have any ITC to claim.

[If the composition dealer has purchased from a regular dealer, the GST charged will be passed on to you as his cost and will increase the cost of the product for you.]

https://blogs.tallysolutions.com/watch-who-you-buy-3-types-of-suppliers/