Takayama-Hokuriku Area Tourist Pass

Can i use this pass in OSAKA for OSAKA loop lines?

Yes, it covers the loop line:

http://touristpass.jp/en/takayama_hokuriku/

http://www.japan-guide.com/e/e2361_takayama_hokuriku.html

It doesn't look like it. This pass gets you from Kansai - Osaka - to Hokuriku area, but not "within" Osaka travel.

WHoops, sorry, my bad.

Well, the page does not explicitly say that transportation within Osaka is allowed, but it probably is, since if it were not they would not really have a way to enforce it...

It is not listed very clearly in the description, but they mention "Osaka Area" include an inset map of the JR conventional lines so seems pretty clear that it's included.

If you refer to the website below, the Area Map cleary includes JR Osaka Loop Line.
http://touristpass.jp/en/takayama_hokuriku/
So, the answer to your inquiry about the availability of Takayama-Hokuriku Area Tourist Pass for JR Osaka Loop Line is yes.