RENTAL INCOME FROM ABROAD

Assuming he is resident the rental income would be taxable under the head income from House property as if it's from normal house property in India. The rent amount would be converted in INR using TTBR rate as on last day of previous year as per Rule 115.
Deduction as per Sec 24a(30% deduction) and Sec 24b(interest) would also be allowed. Even interest paid outside india if it's as per conditions prescribed for Indian house property, will be allowed.

 you need to file correction of your already filed TDS quarterly statement and add challan of Rs. 600 amand can be settled by the system also. without filing correction system cannot recognize that you have paid that 600 against whicd settle that demand to the appropriate column against which you have paid that amount so that the demh liability.