Help!!!!

No, Slade and Robin are not related.
If you read the comics you would understand more of the Teen Titans.
Slade and Robin are not related in both Comics and TV Show

I have no idea!

No, he isn't but what your probably thinking of is when Slade says he could be like a father to Robin, this is actually just a threat from Slade.

Also, Robin's last names Grayson and Slade's is Wilson, so from this you can tell they are NOT related and if they are it's from WAY in the past through like one person and that doesn't count.