hi,i have problems,i have downloaded rigs from internet ,and i have created a character ,now how to can connect downloaded rig to the model,to move it and make animation.please help me.

I’m afraid you’re probably going to have to be far more specific than that. Most rigs are custom tailored for the character that they’re applied to.

As an additional note, you’re probably more likely to get useful help if you name your post something more relevant to your question. Many people tend to ignore threads with ambigiuous or generic titles.

the easiest way to join the armature with the model: select the model in object mode, then shift-select the armature, and hit ctrl P. Heat weighting is the best option in most cases. I don’t know about imported armatures, but it should work if the armature was made in blender. The other thing, though, is 2.5 is not backwards compatible, so if the armature was created prior to 2.5, it may not work in 2.5.

you should be able to edit the armature in edit mode to make it fit.