If you are a tenant, you do not have to pay any comm at all. So I would suggest you skip this one and look for the next unit. Cheers!
If the unit is being represented by the agent who introduce you and he has made it clear that he is representing landlord, you do not need to pay commission as there is no dual representation
However, if the unit he brought you to see is already represented by another agent, Mostly you would have to pay comm on the tenant side unless there is another mutual agreement between the 2 agents.
So the market practice is the tenant would have to pay for his/her side and the landlord will pay his/her side if 2 agents are involve.
There is no such thing as tenant need not pay comm as mentioned by Aaron unless 2 things:
1) The agent who brought you to see the unit is representing the landlord and is collecting commission from him/her
2) The Tenant's agent and the landlord agent has a mutual agreement on the comm which they can share on the landlord's side.
In short, If in doubt about the commission, clarify immediately before tagging with the agent to view units. Usually we be more then happy to explain and clarify
Give me a call if you need further help.