when can a landlord increase rent?

Hi all,

This is specifically for a rent increase in Victoria. 

Being relatively new to property investment, I understand that in Victoria a landlord cannot increase the rent any earlier than 6 month intervals.  However, I have recently advised my property manager to increase the rent on our investment property as of when the current lease period ends.

Things aren't all that clear as the tenants want to renew the lease for one year – which is great – but the property manager says that the rent must be fixed for that period of time that the lease runs for. I would like to increase the rent after six months into this renewed lease – by an amount I will have to look into.  Having a look in prior lease agreements I have had with the tenants, there are clauses that say what the rent will be at the start and another clause that indicates what the rent will be at a certain period in time into the lease.

This property manager doesn't fill me with total confidence either!!

So, can I have the lease set up so that:

1. the lease is for 12 months, and
2. there will be a rent increase 6 months into that lease?

Any reference to pertinent web sites would also be of use.

Thanks in advance.

Glenn1964.