Every script has a limit called Market Wide Position Limit. When many positions are created and it breached a limit like 90%, fresh positions are banned. Of course existing positions are allowed to square off.
Typically it implies accumulation. However entries in the equity is not barred.
The risk mgmt feature of your broker will not allow you to enter the futures contract.
Note if you do enter there is a penalty charged.
Upper circuit is only for stocks not in the FnO list.