INCOME TAX ON LONG TERM CAPITAL GAIN ON LAND SELLING

I'm planning to sell a plot & it gives me approx. 50,000/- capital gain considering indexing, Is there a way I can save paying Income tax on this capital gain, other than investing this amount in new investment.

If i Purchase Capital Gains Bonds under Section 54EC to get an exemption, Do we need to purchase in the tune of capital gains i.e. 50,000 in this case OR for whole sale amount of the plot ?

The land which we are planning to sell is in my mother's name. She has been a house wife through out & never filed ITR. Do we need to declare the capital gain income & file ITR for her ?? The amount is going to transfer in her Saving account only.