Glenda,
You can't increase the rent on a fixed term lease unless it's specified clearly that the rent will increase to a certain amount.
Eg,
Lease Start: 1/1/10
Lease end : 31/12/10
Rent: $1500pcm
Rental increase: $1650pcm from 1/6/10.
There's no need for 60 days notice in this case because...