I am US citizen.If I decide to retire in India for less than 182 days every year, will I become"resident" of India after few years (may be 2) and then I will have to pay tax in India on global income, even though I pay taxes in US. My income consists of social security and company pension. Is US social security payments are tax exempt in India as per treaty even if I am resident for tax purposes in India. If I have to pay taxes on my social security and pension in India, it will be almost 36% vs zero here in US. Does Treaty superceedes country laws??

The tax treaty supercedes the Indian tax law; you will need to pay taxes ONLY to the United States on the Social Sceurity and pension if the pension originates in the United States.

I am a US citizen and have come to India for good. I am being offered employment by a US based software firm and also allowed to work from my home at India. Pl. let me know as to whether this type of employment is permitted under the US and Indian laws and if so what is the tax incidence both in the US and in India. The reply may be given in two situations assuming one that I am a Non-resident, as of now, since I have not completed 181 days in India during the financial year and secondly assuming I am a resident as per Indian tax laws.

You will pay taxes to India, since you are working and living in India.

You will also file a tax return for the United States and declare the income, but if the pay is LESS than $95,000, NO tax will be due to the Foreign Earned Income Exclusion (Form 2555).

If I get SS benefits in India as a NR of the USA,I don't pay taxes on this amount in India and 30% of it is taxed by the US.. any point in filing 1040NR to get a refund from this 30% assuming I have no other US income?

You need to check the Indian Tax Treaty to see if the tax rate is lower (15%). If so, then filing a tax return to get back the difference is wothwhile.