Capital gain exemption claim

If a assessee sold land and building and invested the sale proceeds in new residential property.

However, in 26AS TDS related to sale is appearing but TDS which assessee has deducted and paid, also filed 26qb. While filing 26qb assessee has entered wrong TDS. Can we rectify TDS return, or can we claim Capital gain exemption without rectifying TDS returns.

2) is it mandatory that TDS deducted on purchase of property must appear in 26AS (as tax payer section).