Sir first let us know how you are a citizen of India as your question does not mention your stay in india to give us a clear answer.
We will like to give answer from basics even if you know the same.
The Residential Status of an Individual is to be determined on the basis of period of stay of the taxpayer in India and is computed separately for each year. If an individual satisfies any one of the following conditions-,
he is said to be Resident in India for that financial year. The conditions are:-
1.)He is in India for a period of 182 days or more in that financial year
OR
2.)He is in India for 60 days or more during that financial year and has been in India for 365 days or more during 4 previous years immediately preceding the relevant financial year.
If any one of the above conditions is satisfied, the individual is said to be resident in India. However, if none of the conditions is satisfied, he is said to be a Non Resident Indian (NRI).
There are 2 exceptions to the above rule of classification of Residential Status:
1. In case of an individual, who is a citizen of India and who leaves India in any financial year for the purpose of employment outside India, the 2nd condition stated above shall not be applicable and only the
1st condition of 182 days or more would be applicable.
2. In case of an individual who is a citizen of India or is a person of Indian origin and who being outside India comes on a visit to India in any financial year, the 2nd conditions stated above shall not be applicable and only the 1st condition of 182 days or more would be applicable.
Charge of income under the provisions of Income Tax Act, 1961 is mainly based on :
1.residential status of a person,
2.accrual and / or receipt of income , i.e. within India or outside India.
*****In case of NRI :he didn't fulfill both the situation as he was non resident of India and he didn't received any income in or from India.
And as per sec 139(1) of Income Tax Act 1962, every person has to furnish a return of his income on or before the due date, if his total income exceeds the basic exemption limit.
So ,In case of NRI he has not any income from India ,so there is no need to furnish the return as his income which is in INDIA is less than maximum limit (zero income).
Sir to sum up from what we understand from this is that since your income from India is below the exemption limit there is no need to file the Returns in india whether you are citizen or not.
This is an extract from the Income Tax Act,1961.
Second Option if you really want to file the returns which we think is not necessary : If you are a Resident Indian your global income is taxable in India.This income may have been earned or received outside - but it shall be taxed in India. In case this income is also taxable in another country, you can take benefit of DTAA (Double Tax Avoidance Agreement).