i have a 75 super beetle and need to replace the floor pan.
A friend of mine has a new floor from a beetle, unsure of year possiably in the 60's.

My question is , are floor pans universal, will this fit my baby?

No won't fit, superbugs have a totally different front end to 60s bugs.

Even if it did fit though you are opening a huge can of worms because with VWs the cars identity is in the chassis/floor pan not the body.

For example using a 65 floor pan under a 75Lbug body you would have to have it registered as the 65 which just creates a whole range of other problems.

Just get some new floor pans welded in, whilst it's not a 2 beer job there's shops around that do it all the time.