1. You _______ (yourself /yourselves) don't want to sing the song.

Here I am not clear that It is being said to one or many.

Could anybody explain it?
It is said to one if you use 'yourself' and said to more than one if you use 'yourselves'.

How have you been, Hanuman? I hear little of you these days.
Students: Are you brave enough to let our tutors analyse your pronunciation?
Hello Sir (Mr.M.M)

I am very pleased to hear from you. I am very fine. I am busy with some technical work.

How are you Sir? I want one photograph of you. Can you make it availbale?

Comming to my quetion -

What shall I select (yourself /youselves)? I am not able to get any idea from that question.

Does it indicate something?
There is a problem with the question, then, since both answers are possible. 'You yourself' is singular and 'you yourselves' is plural, and 'don't' is the appropriate verb for both cases.

Email me (my address is in my Profile), Hanuman, and I'll send you a photo of myself if you send me a photo of yourself... and we'll see who surprises whom the most!