My dear (Name),
I am pleased to inform you that my sister’s marriage has been fixed and the marriage ceremony is scheduled to take place on ___________ (date). This is an advance information to you. A formal invitation card is being sent to you separately.
The marriage party will arrive from __________________ (place) and the reception will be held in the Community Centre hall at ________________ (place) which is very close to our residence. The bride-groom is the M.L.A of _______________ (constituency).
I would request you to please make it convenient to attend the reception and the marriage ceremony, along with your parents. I hope, you will truly respond to my invitation. Please convey my regards to your parents.