Not serving Notice period - HR is just delaying the letter as my salary is going to be revised

My Contract renewal was due in Feb 2020 and the HR has not yet sent the renewed contract to me, it is 3 months now.
But I have received my salary for Feb, March, and April 2020 as per previous contract details.
HR is just delaying the letter as my salary is going to be revised, the performance rating and %hike are already declared. After follow - up she is saying, "will revert shortly, and don't worry we will give you the arrears. If I resign in such a case, am I obliged to serve notice period?
And should I claim the HR to complete the FnF with reference to the revised salary?
Can I raise a red flag against the HR person who is delaying the letter?

Dear Member, by virtue of acceptance of Salary after completion of Period of Contract, it is deemed that your Contract has been renewed with retrospective date.To this effect you have received E-Mail communication.You have not given specific details about Terms & Conditions of Contract.Further, you have not mentioned the ground for receipt & acceptance of salary for 3 Months.It will be fair to adhere to Contract for Separation.

I fully agree with the opinion of Srinath. If the contract of employment of an FTC employee is not renewed by the employer and he is permitted to continue and the salary has been continued to be paid on the existing rate, it is implied that the contract stands renewed retrospectively. The statement of the poster that the performance rating and the percentage of the hike are already declared and the assurance of payment of arrears quoting the HR confirms the implied renewal of the contract. If the poster intends to quit at this juncture, he has to serve the notice period or buy it out as per the exit clause of the contract of employment. But there is a possibility of a hidden problem in this - in case the employer does not want to accept his resignation, he may do it under the pretext of enhancing the notice period. If the poster receives the arrears it signifies the acceptance of the renewal of the contract in toto. He cannot accept one part of the contract and at the same time reject the other part for it amounts to approbation and reprobation. Therefore, my suggestion would be to disclose his intention to resign only after the formal renewal of the contract.