Credit of taxes paid in usa

Hi,

An assessee has filed his US Income tax return for year ended 31/12/11. As per the Double Taxation Avoidance Agreement between India and USA:

How much credit is available in India for US taxes paid?

How are Interest Income and dividend income earned in USA taxed in India?

The assessee has LTCG (-11632$) ie a loss. How will this impact his Indian Income tax return?

The assessee hax expired in FEB 2012 and has Retirement account(USA): $617500 AND Social Security(USA): $19808.Will these be taxed in India?

Please reply.