I would start in the spanish section of the RSL official discord.

Please elaborate what would you like to colaborate on ? 

I would like to collaborate as a chat moderator or if it is a lot I could start collaborating where you like.

You  will  need  to  prove  you  are  trusted  in  the  community and  contribute  to  the  Spanish  section of  the  forums  to  be  considered,  they  arent  taking  applications at  the  moment  unless you  get  hand  picked.  Good  luck!  Im  currently trying  for  English moderator also!  :)