some subclass locked?

[StormPharma]

why i can't choose some subclass? what i need to unlock them?

[Psychic Kitty]

That could infact be the sub-classes that have soul trees you have to unlock.

[Lagwin1980]

Probably the storm legion souls which require buying, either get rex in game and buy it that way or pay real money for it.

[SwobyJ]

First 8 souls --> Free

Storm Legion soul unlock (also includes the souls for each class, and is an account wide unlock) --> Costs Credits. Either buy the Credits with $, or grind platinum (the main in-game currency) at max level, buy REX from players on the Auction House, and consume enough REX to get the Credits to buy the souls.
Most reasonable way unless you're a very regular player, is to just buy it with $.

Upcoming 2.7 (geared for the 3.0 expansion) soul unlocks --> Same as with the Storm Legion unlocks, except probably pricier.

[virpyre]

Both the RIFT and Storm Legion products grant permanent unlocks to your account.

Owning the base game will open 1 extra character and 1 bag tab, while Storm Legion will unlock the expansion Souls.

Mage Soul
The Harbinger's strengths include dealing damage to single targets in melee range, and high survivability. While weaknesses include limited area of effect damage.

Warrior Soul
The Tempest's strengths are it's heavy damage lightning rods. They weirld formidable area blasts and have heavy armor with illunsionary tricks It's weaknesses include needing to rely on other souls for heavy melee damage.

Rogue Soul
The Tactican's strengths include the verstile, unleashing torrent bolts along with their healing powers. Their weaknesses include a forced focus on single-target damage.

Cleric Soul
The Defiler's strengths of the class include being capable of intercepting, preventing, and healing through damage. They are capable damage-dealers from a range.