In deployment Phase, both Player deploy alternativly their Units. The one who finish first, gets +1 in the rolloff.
So what count as one deployment?
1. 5 Chaos Space Marines in 1 Rhino?
2. 5 Chaos Spacey Marines, 1 Dark Apostel, 1 Sorcerer in 5 Rhino
3. 3 Obliterators in Transport Chambers
4. 5 Chaos Spacey Marines and 2 Units of Khorne Berserker with 2 Times use of Forward Operative
1) 1 Deployment, as per the rules for Transports in the BRB
2) 5 Deployments, as per the rules for Transports in the BRB
. I assume you're deploying 5 different Rhinos? In which case each Rhino and it's contents are 1 deployment.
3) 1 Deployment, as per the rules for deployment. The Obliterators are a single unit.
4) 3 Deployments. The Chaos Marines, Unit A of Berserker and Unit B of Berserker are each individual units. The Forward Operatives stratagem just lets you change the location of where they are deployed after the fact.
Keep in mind you can't just dump all 5 Rhinos (example 2) or all 3 units (Example 4) down at once, you have to do them one at a time and declare what is inside of it, each such declaration being a single deployment. Also keep in mind you cannot split a unit up between transports. All 5 of those marines would have to be in a single Rhino.