I am working on H1 from August 2017 and will be returning to home country in Februay 2017. Do I need to file returns for FY 2017?

Do you mean that you will be returning to your home country in February 2018?

Yes.

Yes, you must file an income tax return for 2017 and 2018.  Whether or not you file a resident or nonresident income tax return depends on how many days you have been present in the US for the current year and the two years immediately prior to the current year.  A resident income tax return is required to be filed for non US citizens and non US permanent residents if an individual is present in the US for at least 183 days over the current and two years immediately prior to the current year.

The 183 days number is calculated as follows:

• All the days you were present in the current year, and
• 1/3 of the days you were present in the first year before the current year, and
• 1/6 of the days you were present in the second year before the current year.

If you are present in the US for less than 183 days over this 3 year period, you will file a nonresident income tax return (IRS Form 1040NR).

For additional information regarding IRS Form 1040NR, please visit the following website:

https://www.irs.gov/forms-pubs/about-form-1040nr-us-nonresident-alien-income-tax-return

Thanks a lot Eric for your answer