What is cash equivalents?
Yes as cash balance will go negative.
Interest will be charged on negative cash balance of 1.3 lakh from next day as option buying required full cash. Even now this is how it works.
What do you mean by Order here. In general we place order with Multiple Lots. whether the brokrage will be charged per lot or per Order??
It will be charged per order basis. One order can have multiple lots.