Capital Gains Taxation of Tax Free Bonds


I have been trying to find it out, but could not get a definite information. I was wondering if anyone has the information for it. I looked into the below three links, and found conflicting information

Interest on tax free bonds is not taxable but capital gains is -
What are tax-free bonds and how they work - The Economic Times

My doubts are
* is long term cap gains 3 years or 1 year?
* does the gains have 10% (without inflation) and 20% (with inflation) option?
* If I had bought at 1000 and sold at 1300, and current accrued interest is 80, am I right that I calculate the gains on 1300-80=1220?
* Is there any way to avoid paying cap gains tax by investing in capital gains bonds?

Thanks a lot in advance,