Hi,
I was an f1 student from india at Ohio state university,columbus in 2004, during which time I was teaching asisstant.so I had salary from the university.however, I left u.s in 2004 dec. So I did not file state and federal taxes for 2004 year in 2005.I came back to u.s in 2011.I already filed for 2011 and 2012 years. I want to file now for 2004 state and fedral tax returns.can some tell me the standardized deduction as per u.s-india income tax treaty article 21 for year 2004 and exemptions for 2004 year for filing federal tax return.

There is no requirement to file the 2004 return.

The IRS only goes back seven years for tax return filing requirements, and Ohio mirrors that standard.

You PAID taxes; you just never filed the return. A refund was probably due from both the IRS and the state of Ohio, but those refund have long been forfeited.