I want play a mod for 1.7.10 but I [glow=lime,2,300]must[/glow] have got a 1.8.9.

How I play mod for 1.7.10 on 1.8.9?

you cant. you nee to check if the mod is made for 1.8.9/1.10.2

update to 1.10.2

Why I update to 1.10.2?

The mod is only for 1.7.10!

1.7.10 is not supported here

Minecraft versions between 1.7, 1.8 and 1.9 have a lot of changes in them. A mod for 1.7.10 only works for EXACT that version. A mod for 1.8 only works on 1.8 and a mod for 1.9 only works for 1.9 (and maybe 1.10, this is an exception because there are only little changes so mods from 1.9 may work for 1.10). But other than that mods work for exactly that version they are made for.

 

If you want to play an 1.7.10 mod you MUST play 1.7.10. 1.8.9 is pretty much a dead version now, so it's likely most mods will never be updated to 1.8 If they aren't already.

In addition to what pWn3d said, keep in mind that even 1.8 mods will usually not work with 1.8.9, and likewise many 1.9 mods don't work with 1.9.4.

 

A lot of 1.9.4 mods DO work with 1.10.2, though. This is a relatively rare case, though, as not many internal changes affecting mods were made between the 2 versions in either Minecraft or Forge.

 

1.11 is expected to have several changes which will probably affect at least several mods, causing at least some, if not complete incompatibility with 1.9.4 and/or 1.10.2 mods.