I don’t think broker can legally sell your holdings. But, if sold(by you or anyone else), it’ll cover the negative balance first. So you can’t take that money either. The above doesn’t hold true, if stocks are pledged. Pledged holdings can be legally sold by broker anytime to cover, if there’s a negative balance. This is called a margin call. Though, zerodha staff here havea “unwritten” rule, that they only sell if margin drops below 60%
Official:
Your positions will be squared off at the discretion of Zerodha if you don’t add the required funds within the specified time.
Interest is usually 18%pa in this case.
Margin penalty:
Not sure if there will be margin penalty, since it becomes a CNC trade.
Unwritten word of mouth:
That is if it is 60% of value of pledged holdings or cash available. Ofc, if there’s nothing to square off and stock can’t be sold, you’ll be paying interest as “Delayed payment charge”(along with margin penalty if any.)