Non Resident Indian taxes 2016

1. Are we filing the correct forms? are they adequate?

Maybe. 1040NR or 1040NR-EZ is right if you are a nonresident alien for federal tax purposes. Usually if this is within the first 5 calendar years in which you are an international student (e.g. for filing 2016 taxes, if you came on F-1 in 2012 or later), you are a nonresident alien.

For California tax purposes, whether you are resident or nonresident doesn't have anything to do with your immigration status. Usually if you live in California I would consider you to be a resident. But resident or non-resident doesn't make a difference if you don't have income from outside California.

2. Where will contribution to 401(k) appear in tax filing? Will it appear under 17 a (Pensions and annuities) or under Itemized deductions?

Generally, nowhere.

3. If Standardized deduction is claimed (Line 38 of Page 2, Form 1040-NR), will it appear on Page 5 (Schedule OI) under L-1 (Tax treaty)?

I don't think so. That's for income that is excluded from being counted as taxable income, which is different from being able to use a deduction.