Hi,
First of all thank you for startging such a nice forum.
My Question: Right now I am on L1 and working for a multinational company.
I am plannig to change my status to F1. Lets say If I apply and I get approval when can I resign from Company as notice period is 15 days and I would never know the start date of my F1.
Legally, you will be on F-1 from its effective date and need to stop working on L-1 from that date.
I think you can mention the start date when filing the COS. So if you know when your school is starting you can give that date, and see if it gets approved prior to that. This will give you enough time to give the notice period.
If there is an overlap, and you really want to give the notice period, then also it should be fine. It will be a gray area and USCIS can question about these 2 weeks. Their acceptance will depend upon whether they are convinced by your reason or not (i.e. notice period).