T1, T2 and T3 Items have no level requirement so you can use a skill rank req 10 rod since its T3.
But your progress gets slower if i remember right from my fishing expirience.
Use skill-req rods around your rank and your fine.

So I need to have a fishing profession rank of 15 to use the the T4 rod?
Just making sure I have this correct.

nope, i use a IV rod 95 dura(skill rank 15) , i have fishing prof 6.

Skill rank 15 means its the last level you get experince fishing with that rod. When you reach fishing prof 16, you want to use atleast a V rod

This post was edited by sp_patl on Jun 30 2015 10:50pm

Thanks for that clarification! So right now the T4 rod is unequippable, what do I need to do to be able to use it?

Should be rank 5 to use t4

I believe the rod stays red until you level up your character to level 5.
Not fishing level, character level

IT stays red just indicating your char is not on that level but it can be used. You can use a level 50 rod on a level 1 char.
It is safer to use a rod 4-5 levels above your fishing level to keep it from breaking, but reeling in is a bit slower.