I think the bill doesn't mention gays or gay weddings, its general enough in verbiage that it would apply to those businesses who object to mixed race couples by claiming its religious grounds, which would be rejected by the court regardless.
Indiana General Assembly :Senate Bill 568 : Religious freedom restoration act
Religious freedom restoration act. Provides that a state or local government action may not substantially burden a person's right to the exercise of religion unless it is demonstrated that applying the burden to the person's exercise of religion is: (1) essential to further a compelling governmental interest; and (2) the least restrictive means of furthering the compelling governmental interest. Provides that a person whose exercise of religion has been substantially burdened, or is likely to be substantially burdened, by a state or local government action may assert the burden as a claim or defense in a judicial proceeding, regardless of whether the state or a political subdivision of the state is a party to the judicial proceeding. Allows a person who asserts a burden as a claim or defense to obtain appropriate relief, including: (1) injunctive relief; (2) declaratory relief; (3) compensatory damages; and (4) recovery of court costs and reasonable attorney's fees.