Question

Rama may be either in the house or in the garden........ check for grammar mistakes

Answer 1

rama must be either in the house or in the garden

Answer 2

Rama may be either in the house or in the garden. this sentence is absolutely correct if you don't know where Rama is and have a doubt if he is on the house of in the garden.

Rama must be either in the house or in the garden. its correct only if you know perfectly where Rama is, he surely be on the house or in the garden.