Razor Shark is pretty garbage unit, Storm Raven is pretty great
Let's turn the Razor Shark into a Tau Storm Raven!
Let's see to replicate the 2x Hurricane Bolters...
A Pulse Rifle is basically the Tau equivalent of the Bolter
So we essentially need a Pulse Rifle that shoots 6x...
Then again a Pulse Carbine is equal to a Pulse Rifle...
So we need a gun that's similar that shoots 12 times.
How about we just use 3 Burst Cannons
Edit - Correction... They have 2 Hurricane Bolters... not 1
So this should be 6 Burst Cannons
To replicate the Twin Heavy Bolter... Well, a Burst Cannon is basically a Heavy Bolter... so let's just say 2 more Burst Cannon
Assault Cannons are basically 2 Heavy Bolters, shorter range but better strength
So we could say it's 4x Burst Cannon
With of course the option of replacing them with another Heavy Rail Rifle.
Let's see, it also has 2x Stormstrike Missile Launchers, which equals more or less a Heavy Rail Rifle
Obviously it will come standard with a Target Lock, so it can move and shoot Heavy Weapons with no Penalty
To recap...
9 Burst Cannons with a Heavy Rail Rifle
Option to replace 4 Burst Cannons with another Heavy Rail Rifle
Edit - New recap is 12 Burst Cannons with a Heavy Rail Rifle
Option to replace 4 Burst Cannons with another Heavy Rail Rifle
Let's call it BS4, T7, with a 4+ Save
250 points