There is no fixed dress code in India for marriages. And in functions like ring ceremony or sagan, which happens to be one of the first ceremonies between the two individuals and two families getting united, perhaps anything is admissible. Among most Indians sherwani/kurta-pyjama is a common dress.
As the typical English dresses like shirt-pant and blazers are becoming the only option in work places and also at most times, ceremonies remain good occasions for preservations of traditional Indian dresses. There has been enough debate however, as which dress is preferable. It is a fact however, than in spite of their encumbrances, traditional Indian dresses still excel as the most comfortable choices in the Indian climatic conditions, especially in a ceremonial occasions with gatherings. There is no denying the fact that a suit or a blazer gives a smarter look. But sometimes these may be quite uncomfortable in ceremonial occasions, at least for the groom, if not the guests.
Check out nearby groom wear vendors in your area