Holding objective

[Tizianolol]

Guys if I have no unit to protect an objective,  but its in my deploy zone  or I conquest it last turn,  its considered still mine? Or I have to put into it at least 1 model ? Thx guys!

[GrimDork]

Core rules, page 10, box titled Objectives, 4th paragraph says “Once you gain control of an objective, it remains under your control until the enemy is able to gain control of it.”

So, once you have claimed an objective you can move off it and still control it.
Check the battleplans tho, some battleplans have different rules which replace the normal rules. Places of Arcane Power & The Better Part of Valour for example, where you lose control of the objective if you move away from it.

[jamie.white]

Usually once you have taken an objective you control it  and can move off it , however it’s worth checking the battle plans as some require you to stay on it 

[Brandfas Machine]

It's also worth noting that just because an objective is in your deploy zone doesn't mean you have automatic control over it; you must still capture the objective by ending a turn with models within 6" of it.