Hello Uncle,
you can receive the proceeds from the sale of the house property in your saving bank account. and within six months of the sale transaction you are required to invest only the capital gain(NOT the whole proceeds) amount in bonds under section 54EC.
you can take fair market value of your house as on 1st April 1981 as the cost of the house. you can get registered valuer report to justify fair market value of your house to calculate the capital gain from the sale of the house property.
As your house was constructed before 1981, there is no need to have all the documents, you get the valuation done to arrive at fair market value as on 1981.
if you are not planning to purchase or construct a house within period of 3 years, there is no need to deposit the capital gain amount under CGAS.
it is only applicable where you have planning to purchase or construct the house in near future.
So you can get the sale proceeds in your bank account. if the amount of sale exceeds Rs 50Lakhs the buyer is required to deduct TDS of 1% from the sale proceeds you can claim later by filing your return