If you are an NRI/OCI/PIO, you would have to file your income tax returns if you fulfill either of these conditions:
(a) Your taxable income in India during the year was above the basic exemption limit of ` 1.6 lakh OR
(b) You have earned short-term or long-term capital gains from sale of any investments or assets, even if the gains are less than the basic exemption limit.
Note: The enhanced exemption limit for senior citizens and women is applicable only to residents and not to non-residents.