(always state your language, but I can tell you're talking about the C code) ... which is giving you m and n both as dimentions, although the description states the matrix will be n by n ...

The first step to help you with your problem is posting in that kata discourse, not here. There you can post your code using markdown formatting and marking your post as having spoiler content.

Indeed, check this for example:

Testing for: n = 392095 what is the max number you can get deleting a single digit?

But than the problem becomes find the smallest digit in the number and remove it,or not?

No. You're supposed to find the maximum number you can get by removing exactly 1 digit.

Because it's tagged as Puzzles and Games. And that is part of what you have to figure out to solve the kata.

You're not supposed to rearrange the digits. If you remove one digit without rearranging, the max number is 101.