Since you are an NRI the exemption can be claimed or return can be filed in the NRI circle in any metro city. There is no need to furnish proof of tax liability in the other country since you are not availing any tax credits involving DTA. Redemption of equity-oriented fund, which is long term in nature, is exempt from tax by the finance Act of 2004. Retrospective claim of TDS is possible and the procedure would take about 2 years.
Income distributed from the coop society is not agricultural income but treated as income from other sources. Finance Act 2004 has only a prospective effect unless a specific proposal states that it has retrospective effect.