sickjoce wrote:if i instal this can i play the guys with normal patch or only with this patch?
No you can't. You can only play with people using ITST mod. Anyway, you could have 2 differents installations of Tennis Elbow in your computer (in different folders, of course): One unmodded to play with people without any patch. Second one with ITST patch, to play with others ITST users. Also you can have more installations (with Sam's patch for ex).
I think that ITST mod provides the best online tennis experience by far, so i suggest you to try it, but it depends of yours preferences: with or without helpers or previews, sim or elite controls, real players or created, etc...