applicability of income tax act

1. According to sec 1 of the Income tax Act 1961. It extends to the whole of India. 
2. However, sec 10(26) exempts certain income earned by Scheduled Tribes of Arunachal Pradesh. It read as  in the case of a member of a Scheduled Tribe as defined in clause (25) of article 366 of the Constitution, residing in any area specified in Part I or Part II of the Table appended to paragraph 20 of the Sixth Schedule to the Constitution or in the States of Arunachal Pradesh, Manipur, Mizoram, Nagaland and Tripura or in the areas covered by notification No. TAD/R/35/50/109, dated the 23rd February, 1951, issued by the Governor of Assam under the proviso to sub-paragraph (3) of the said paragraph 20 as it stood immediately before the commencement of the North-Eastern Areas (Reorganisation) Act, 1971 (81 of 1971) or in the Ladakh region of the State of Jammu and Kashmir, any income which accrues or arises to him,—
(a)  from any source in the areas or States aforesaid or
(b)  by way of dividend or interest on securities;
3. From the above reading, we can conclude that only the above two incomes are exempt from payment of tax and for other income IT act normal provision will be applicable. 
4. To answer to question "Income-tax Act will be applicable to people of Arunachal Pradesh"
Please correct me if the above solution has an alternative view.