Hello, I have been able to get to the 3rd interview but there are a few things about the job that I am not "too happy" about.
I would like to hear your advice on how to address these concerns in the most tactic way.

Basically I applied for a job in NYC, at the first interview HR mentioned that I'll have to go to the NJ offices MAYBE 1/week, at the second interview the department manager told me once/month... and I am afraid that going on like this, at the third interview they will send me directly to the New Jersey offices period.
Please let me clarify that the ad didn't mention anything about working in the New Jersey office, the job opening was for the New York city offices.

Plus, the salary is not that great but I would have been fine if they weren't asking me to commune for 2 hours every week or more.

Any suggestions?

Thanks!

When you get to the interview, ask the interviewer, in a matter-of-fact manner, how often, if ever, you'll be required to travel to the NJ office. Advise him/her, in a non-accusatory, non-blaming matter that you've been given inconsistent information and would just like to clarify it to be sure. Then, if they do make you an offer and you feel that the commuting expenses will be an inordinate burden, you can try to negotiate for a "commuting allowance" or whatever you'd want to call it. Also, keep in mind that some of your commuting expenses will be tax-deductible and they could probably advise you further in that regard.

I'd do it at the end of the interview, and I wouldn't say anything about inconsistent information. Never make the employer wrong in an interview, just say you're a little confused.

Remember, if they offer you the job you are then holding some of the cards and you can negotiate your employment terms more specifically.