What does circuit limits i.e price bands mean?
These are safeguards set to prevent large moves in the stock in a very short time and when the price changes above or below the limit, trading is halted on the stock. The price band is the range within which the scrip can be traded without being halted.
Orders placed out of the price band will be rejected, and if the price drops to the upper/lower price band trading will temporarily be halted. F&O stocks have dynamic price bands in order to prevent erroneous order placement.
For more information refer the below links -