Question

into indirect speech Mr das asked his wife why is the baby crying​

Answer 1

It is already in indirect speech I think you want it in direct speech
Mr. Das said to his wife, " why is the baby crying?"

Answer 2

The correct question is :

Mr. Das asked his wife , " Why is the baby crying ?"

ANSWER :

Mr. Das asked his wife why the baby was crying .

DETAILS :

The reported speech is in past tense . Here the reported speech is the word that is before the negative . Here the word is "asked" and hence it is in past. The tone of the entire narration will be past.

Also the question mark sign present in the question has to be removed .

The sentence has to be converted to assertive from interrogative . Thus we will remove the question mark and insert a full stop.