Income tax itr v

Dear  Experts,

After uploading the IT return on line, the Hard Copy of the ITR V was signed and sent to CPC Bengaluru as usual by Speed Post.

However, received an intimation saying that the ITR V is rejected and the reason for rejection as shown is " The tax payer has not validated" 

Could you please inform what does it mean and what should be done now.

Regards.