I want to know that in a tender the Delivery clause stipulates for
material to delivered in three equal quaters.We delayed in first
qurter and second quarter but comleted the delivery of the entire
before the end of third quarter.Hence the overall delivery was
completed within the stipulated time.The clause applied was Liquidated
Damages.There was no loss of revenue or no extra cost to the
client.Can the liquidated damages be waived

I do not pretend to answer your question, but some clarification may be needed

1) was it an installment contract? Did they have to pay on each
delivery or in one lump sum after the last delivery? Did they accept
each delivery and paid for it?
2) what was the amount of liquidated damages as compared to the whole
contract price?
3) how big was the delay? at issue will be whether the breach was material or not.