Is wearing sehra on the day of marriage by men unislamic
As the bride is made to wear flower garland and ‘sehra’, can a groom also wear a ‘sehra’ (flower turban) and garland at the time of Nikah? If it is Haraam in Islam, what would be the reason for it. Please explain.
Nothing of that sort is Haraam in Islam. These are the things that have to do with the customs of a society. Islamic teachings would only require us to avoid doing things that are disallowed in these matters, like doing shirk, getting into obscenity etc.