As per BIS Act, 2016 and Bureau of Indian Standards (Conformity Assessment) Regulations, 2018, BIS has the authority to provide the license to the foreign manufacturer to sell products in the Indian market.
FMCS BIS certificate is only granted to those manufacturers whose product conforms to the Indian Standards. Though, these standards could be voluntary or mandatory.
https://www.jrcompliance.com/fmcs-bis-certification