I applied for my mom visitor visa extension but it is almost 6 weeks and date is till Dec 1 and there is no update? What should i do next?

Two choices: Either wait until you get the approval letter or denial letter. If approved , everything is okay. if denied, you will hold on to the letter and carry it each time they travel back to US to explain CBP at POE why they overstayed visa in case if they ask. Or, they leave on date before the expiration of the i-94 date. They are taking usually between 7-9 months to make decision.