Hello,
You should convert into USD using the following rate of 66.768 Rupee for 1 US $ (average for 2015). This is in the IRS table Yearly Average currency Exchange changes.
About the pension, it should be included in Other Taxable income (under Wages & income). If you have paid taxes in India, then you should also report them as passive income and deduct the taxes paid under Foreign Tax Credit section.
