Hello Aairah-Rizvi,
Usually, whenever any employee resigns, company withholds employee's salary during notice period and pays it during Full and Final settlement. It is only to make sure if the concerned employee has any dues payable to company, whether employee is giving his charge handover properly etc. before official relieving.
It seems you have 2 months' notice period. So you have not received salary for October, 2020. I suggest you to have a friendly dialogue with your HR about the salary withhold and also with an intention to understand the Exit policy.
Aim to have a graceful exit. All the best!