Why are my brake light and battery lihgt flashing off and on

Are you referring to warning lights on the dash board? The flashing battery light may mean you have a charging problem and the flashing brake light may mean you need break fluid or have an other brake issue. Take it to a service station or the dealer. Or read the owners manual.

possibly has flat battery and the security system has lock in get new battery and try then, you will have to lock and unlock via fob after fitting new battery to reset the security system good luck

what light?. i've no idea what that means..
the operators guide names all lights.
name it or show a photo. or ? RTM or read the FSM.

post all symtoms , including light location and color and shape.

This may have been caused by low battery voltage, have the battery load tested by a local parts store like Autozone, it is free.

If you are talking about the back-up lights, check the bulbs and the back-up light fuse. You could have a problem with the switch which is part of the neutral safety switch on the transaxle.
If the brake lights don't work, could be the bulbs, the brake light switch, a fuse, or the turn signal switch.

You must turn the key to CRANK then release the key to the ON position without turning it off for the pass key system initialization procedure to work. The security lihgt will not syop flashing if you do not do it this way. It also helps to install a battery charger before doing this so the system voltage does not drop too low while you are waiting for the security light to time out.
You may also have to repeat the procedure three times before the engine will start.

did you check the fuses under the hood? There should be a 20 amp brake light fuse in there.

check brake light switch, under dash on steering column where brake pedal meet

BRAKES! Replace your brakes NOW. You have less than 2MM of pad lining on (most likely) your front brake pads. No brakes, no stop. No stop, no MINI.

check to see if your brake lights are working if they are not working check power to the brake light fuse if its ok the brake lihgt switch maybe bad if the power is not getting to the shifter lock from the brake light switch the car will not come out of park