Did Abraham Lincoln have the right to free slaves in the rebellion states?

It would depend on whether you were from the Union North or the Confederate South.

Technically, the President does not have the power to do this, except insofar as it was part of his war powers. He could tell the armed forces to do it, but legally, he needed congress to back him up with a Constitutional amendment.

It is up to the Congress and House of Representatives to pass laws and for the president to sign it and for the Supreme Court to decide if the law is constitutional.