" I found that NRI should compulsorily file ITR2 even for claiming TDS refund on NRO account. Is any particular Section present in IT Act? "
YES.......
Extract from the norification 16 of CBDT dated 03.04.2018
(As amended to notification21_2017 )
".........In the Income-tax rules, 1962 (hereinafter referred to as the principal rules), in rule 12,−
(a) in sub-rule (1),-
(I) for the figures “2017”, the figures “2018” shall be substituted;
(II) in clause (a),― (i) for the words “an individual”, the words “an individual who is a resident other than not ordinarily resident and” shall be substituted;.......... "
(ii) in sub-clause (ii), after the words “brought forward loss”, the words “or loss to be carried forward” shall be inserted;
(iii) in the proviso, for item (I), the following shall be substituted, namely:- “(I) has assets (including financial interest in any entity) located outside India;
(IA) has signing authority in any account located outside India;
(IB) has income from any source outside India;
(IC) has income to be apportioned in accordance with provisions of section 5A;”; ...........
" .........Provided that the provisions of this clause shall not apply to a person who,—
(I) is a resident, other than not ordinarily resident in India within the meaning of sub-section (6) of section 6 and has,—
(i) assets (including financial interest in any entity) located outside India; or
(ii) signing authority in any account located outside India; or
(iii) income from any source outside India;
(II) has claimed any relief of tax under section 90 or 90A or deduction of tax under section 91; or
(III) has agricultural income, exceeding five thousand rupees;.........."
Refer: Revised-update-on-IT-Rule-12-w.e.f-1.4.16.