Can my rent be increased without notice?

Okay, I think that they are trying to pull a fast one. I would really like to see a copy of this agreement to e able to tell you what is going on but since that is not possible, I will give you some generalities that hold true.  I do think that you should seek some help from an attorney of a tenant;s rights group.  Now, the landlord is the owner of the property and if he or she signed the lease then it is not "null and void."  Same holds true fr the realtor if the realtor signed as agent of the landlord. Why they are both on the lease I do not know.  But the contract stays in effect from the start date to the end fate and as I see it from here you have 8 more months at the rent agreed upon.  If they dare to try and evict you stand your ground and when you get to court show the Judge your peace.  Good luck. 

No, your rent may NOT be increased during the middle of a lease term, so long as the lease is in force. And also, your  prior lease *should* still be in force, unless you did something which violated or breached  a material term of it--in which case, you could be evicted. Changing a realtor, or building management company, or etc. does not invalidate, terminate, or void a lease--the lease remains in effect despite a change in whomever the landlord is working with. Similarly, if the landlord sells the building, the buyer is bound by the leasee, too. Only in the event of foreclosure (for, e.g., nonpayment of mortgage or taxes) is a lease terminated--though even then it does not occur immediately, and there are some legal protections for tenants. But overall, as long as you honor your obligations under the lease, the rent cannot be increased during this lease, though the landlord can certainly increase it when this lease expires.