A question..........

Hello, Im new to this forum and just currently tried MHFU. So here my question, how do I beat high rank red khezu? Currently my armor for blademaster is full Tigrex. While on the gunner ive got full Ceanataur. Please state a good weapon for killing red khezu.

Opposite to normal khezu , red khezu has a weakness in water.
Generally speaking , khezu is easier to take on with a shield as you can block that thunder charge and take small (almost no) damage.
Buuuut I would personally suggest the Rapier dual swords and it's upgrades. They have helped me taking it down since my first red khezu. These : http://monsterhunter.wikia.com/wiki/Order_Rapier

I'd gun the Khezu. If it were the normal white variant I'd use the Melynx Ragdoll/Helldoll, but for Red I might as well go for the Assault Conga+. Khezus aren't long, but Pierce S Lv1 does 3 hits, and the AC+ fires bursts of 3, so with Pierce S Up you might kill the Khezu before you run out of shots.

A few extra reasons for Assault Conga+:
With Bullet Limit gemmed in (Shot Mix), you'll be able to mix loads of Pierce Lv1, meaning you'll have a ton of ammo at your disposal either way (60+99x3= a grand total of 351 shots, 1053 shots with the Rapid Fire)
It'll come in handy for Lao and Shen Gaoren with that. And if every shot hits perfectly, that's a whoppin' 3159 hits! I soloed High Rank Shenny with that and Mazereon's guide in 25 minutes with the fort at 70%.
Huskberries can be bought for 1z at the shop or farmed, while the Peddling Granny sells Velociprey Fangs from time to time. I suggest keeping several stacks of Fangs to avoid constantly buying things.

I normally use a Bow to fight the Red Khezu. Try making the Daimyo Warbow, since its a water element bow that also uses pierce shots, so you can play on its weaknesses. Using a bow makes it really easy to dodge, but be careful not to get comboed if you do get hit.