According to the ARTICLE 24 (2) of DTAA between UK and INDIA :
" Subject to the provisions of the law of India regarding the allowance as a credit against Indian tax of tax paid in a territory outside India (which shall not affect the general principle hereof), the amount of the United Kingdom tax paid, under the laws of the United Kingdom and in accordance with the provisions of this Convention, whether directly or by deduction, by a resident of India, in respect of income from sources within the United Kingdom which has been subjected to tax both in India and the United Kingdom shall be allowed as a credit against the Indian tax payable in respect of such income but in an amount not exceeding that proportion of Indian tax which such income bears to the entire income chargeable to Indian tax. "
india-uk dtaa link : https://www.allindiantaxes.com/uk%20.php
Therefore income first to be included in TOTAL INOCME and from the tax caluculated as per indian tax rate ,credit shall be given of tax paid in usa in rupees.
% of credit to total tax should not be more than = % of uk income to total income
exchange rate prevaling on the date of receipt of income shall be taken.
this website will help you find exchange rate on particular date : https://www.xe.com/currencytables/#
now lets take your case and assuming:
indian income =12,50,000 and
exchange rate on date of GBP income = 1GBP = 97.82 RS
SOLUTION:
Indian Income = 12,50,000
GBP income ( 43,086 * 97.82 ) = 42,14,673
GROSS TOTAL INCOME = 54,64,673
Less : dedcution 80C = 1,50,000
TOTAL INCOME = 53,14,670
TAX as per indian rate = 14,61,984
Less : tax paid in UK ( 7076.53 * 97.82 ) = 6,92,226
TAX PAYABLE IN INDIA = 7,69,758
( interest 234A/B/C not calculated)
checking the condition of credit limit :
(a) % of uk income to total income = 77.13%
(b) % of credit taken to total tax = 47.35%
since (b) is less than (a) therefore full credit allowable .
RETURN FILING : You have to file ITR-2 . WHY? because in ITR-1 there is no provision of DTAA relief . and to get that relief you do'nt have to go to ITR 4 , ITR-2 is sufficient .
After filling , your important schedules :
1.Part B TTI
2.Schedule FSI - tax payment outside india
3.Schedule TR - claim
WILL SOMTHING LOOK LIKE THE IMAGES in ATTACHED FILE .