Hello i have seen people saying that Valerian is diuretic and some antidiuretic, i just wanted to know which one it really is.

its is a naturally occurring herb and not a drug. thus it has not been studied in any detail nor is it covered by licencing regulations.

You are correct there are statements made on-line for both dietetic and antidiuretic properties. The evidence for those statements however is murky at best and no formal studies have been reported in the scientific literature.