I am a new fisherman, and have bought an older model shimano caenan 101 with 6:5:1 ratio. I just don't know what would be the best size rod for it. Any help? 

The gear ratio does not necessarily indicate what did it should be paired with. If you are fairly new to fishing though I would try to find a rod that is a 7' MH. That should make for a good all around set up.

Choose a Rod to compliment the lure, technique and cover you wNt to fish not a particular reel. 

So another question.  What size rod is used for specific techniques? 

7 hours ago, Brokenparatrooper82 said:

So another question.  What size rod is used for specific techniques? 

Depends on the technique. If you want a good all around rod a MH F is hard to beat.