Traditional IRA distributions taxation as non-resident

IRA distributions are not pensions or annuities as far as US law in concerned and so I don't think that Article 20 applies to them. I believe that what does apply is the Relief from Double Taxation clause which says in Section 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."

If my belief is correct, then there is no advantage to converting a Traditional IRA into a Roth IRA (paying taxes on the value in the year of conversion). Take distributions from your Traditional IRA after turning 59.5 (from which 30% will be mandatorily withheld for US income tax since the money will be going to a non-US address). Note that tax withheld is not the same as the tax due; the latter amount is determined only when the US tax return is completed, and if the 30% is too much, you will get a refund of the difference. Yes, the total amount (that is, without the 30% withholding removed) will be taxable in India again, but you will get a credit against the income tax due to India in the amount of taxes paid to the US; not the 30% withheld. Also, be aware that the Indian tax year (April 1 till the next March 31st?) is different from the US tax year (which is the calendar year January 1 to December 31).

Oh, and India and the US don't have a tax treaty (the US Senate did not vote to approve it, as required by US law) but do have a DTAA (Double Taxation Avoidance Agreement) which doesn't have the same status as a tax treaty.