On internet, I found the following. It may be helpful for you.
As per the Article 16 of DTAA ,salary is taxable in both India and USA if you have not spent more than 183 days in USA.
However , relief for tax paid in USA is given under Artilce 25(2) of the DTAA between India & USA deals with credit for tax paid by Indian resident in USA .
The said clause is as under
"2. (a) Where a resident of India derives income which, in accordance with the provisions of this Convention, may be taxed in the United States, India shall allow as a deduction from the tax on the income of that resident an amount equal to the income-tax paid in the United States, whether directly or by deduction. Such deduction shall not, however, exceed that part of the income-tax (as computed before the deduction is given) which is attributable to the income which may be taxed in the United States."
So whatever you EARNED in USA will have to first be included in your total income in India and tax will be computed as per I T Act . From there the TAX paid in USA shall be deducted .
The formula for computed the amount of deduction is applicable only for section 91 of the I T Act which is for countries with which India has no DTAA.