ISSUE:

You mean p-methylaniline and m-methylaniline

p-methylaniline is more basic, the methyl in the para position destabilizes the third structure by giving up charge due to an inductive effect.

In case of putting the methyl in meta, since the negative charge does not pass through the meta position, the methyl and the charge never coincide on the same carbon. This base is more stabilized by resonance and is therefore weaker.