RESTRICTIONS & CONDITIONS OF COMPOSITION SCHEME DEALERS :
As per the Provision of Section 10(2) clause (b) of the CGST Act 2017, A person registered under Composition Scheme will not be allowed to sell any "Non-Taxable Supply of Goods" ( like Alcoholic liquor for Human Consumption, 5 Petroleum Products etc ).
However they are eligible to Supply Exempted Supply.
Note that Exempted Supply and Non-Taxable Supply are different.