In my opinion, you should take risk and lock part of your amount if you have surplus money in RGESS.
This would be better than NSCs if you hold for a long time of period.
I am sure fund managers would try to make it to list above NFO price initially at least.
NSCs give you nothing after inflation (-7-9 %) and tax deduction (-?) .
People in INDIA still will feel that RGESS is better option other than tax saver mutual funds available in market.
Happy Investing !