why in case is यह and not इस?
Because it is a question and no possessive or oblique case is there
This sentence is for blind people. But hey, I don't judge :)
Or colorblind people.
This is definitely Aamir's room
Is this room is green ..this sentence correct ??dulingo reject it
Answer is 'Is this room green', your grammar was wrong.
I think you are giving very less time and big big sentences