Question

I said to my class teacher, " may I come in" change indirect form of speech

Answer 1

it means she asked to her class teacher directly
so indirect
shall I come in
May be it helps u

Answer 2

I asked my class teacher if I can enter the classroom.

Here the sentence has been changed from direct to indirect speech without changing the meaning.

Here the conversational tone is altered and is written the sentence into a descriptive manner.

The use of tense, sequence, and the best description of the situation is maintained while converting it from direct to indirect.