i am new to the forums and i have been playing the game for quite a while and i am wondering is there a mod that you start to the acient age but all techs stop at renasaince age so you just have medival units.

I don't think that there is a mod for that. There is a thread somewhere in the Ideas + Suggestions forum about this. If I find it I'll get you a link.

Welcome to the forums!

Edit: Here's the link (http://forums.civfanatics.com/showthread.php?t=277057)