Question

I have to make a comic strip based on any episode of Tom Sawyer book of class-7 NCERT

Answer 1

I have no idea what is meant by "book of class-7 NCERT" but see if you can find some ideas here:

https://www.sparknotes.com/lit/tomsawyer/

I'd look for a sequence between him and another main character when something central to his character was made clear. For this type of thing, read the section on Themes and the character analysis of Tom himself.