How to increase the number of bytes per line in frame section ?

I'm assuming that by "the frame section" you mean the hex/ASCII dump pane which is, by default, the bottommost pane of the display.

If so, then the answer is "edit the source code for the hex dump pane and recompile." :-) There's no preference to change it to any value other than 16 bytes per line; presumably you have a very wide display that could handle more bytes.

Why is this an issue? Perhaps there are other ways to solve the problem.