is it possible to get a job in nyc but live in philadelphia and do companies ignore your application if you are out of state.?

It's possible, but that would be quite a commute if you were required to report to the job site every day. Depending on how you planned to make the commute, it could easily take up to and over three hours one way. That's over nine times the normal commute time nationally. 

They won't likely ignore your application based on where you live because they might assume that you are looking to relocate.  But it could come up in an interview and they may ultimately choose someone who will be living more locally.  It could be assumed that someone more local will encounter fewer commuting-related problems than someone farther away. 

That being said, I have family in Philadelphia and one of them did work in NYC while still living in Philadelphia.  They were not happy with the commute time though.

It's possible, but it highly depends on the line of work you're in and how much in demand you are.  I knew someone 10 years ago who did that.  He commuted once or twice a week and worked from home the other days.  He was also highly regarded in his field.  On the flip side, if you're looking for a job at Starbucks it's unlikely they'd consider you.

Technically yes; but if you have to be in NYC to work, this is likely to count against your application (less convenient than someone who's already local)

It would depend on the company. I would think tho, that they would be expecting you to relocate to NYC if they did find you to be the best person for the job, as a 2+ hour commute each way is going to be a bit of a btch, and they would probably choose someone closer if you refused.