Question

I said to Gopal can you come tomorrow change the narration

Answer 1

I told Gopal that could you come the next day

Answer 2

First let me ask you whether the question you have written is in direct or narrated speech...because you have used the word 'said' but not used inverted commas...

If it is in direct speech

I said to Gopal ," Can you come tomorrow ?"

If it is indirect speech

I asked Gopal whether he can come the next day.

HOPE THIS HELPS