The radiator will need to be replaced.
Sometimes, it may seem that the radiator itself is leaking but it could be the radiator "hose" that is leaking. In this case, the radiator hose needs to be replaced and clamped tightly.
Replace the radiator with a new or good used one.
A car with a leaking radiator can be driven, but when the coolant leaks out, the engine will overheat and when the engine gets hot enough, it will seize-up, the car will stop, and the engine will have suffered severe damage.
If coolant is leaking from a car it means that your radiator has a hole in it. If this is not fixed the car will over heat.
Thermostat and radiator
Probably your radiator fluid leaking out.
It is leaking coolant or the radiator cap is faulty.
Then you either have a blown head gasket or a cracked head. Stop driving the car immediately an have it repaired. A rare possibility is that the transmission cooler inside the radiator is leaking fluid into the cooling system.
If your radiator is leaking then you will need to replace it. Additionally, if you find that your car is constantly running hot you will need a new radiator.
If a leak exists, there should be green or red fluid leaking from just under the nose of the car. It is possible that the engine must be running for the leaking to occur, but this is not always the case.
Green fluid leaking from a car is radiator fluid. "A professional certified mechanic can handle the repair or maintenance needed to fix this issue."
there might be a leak some where in a coolant line. or maybe you have a leak in your radiator.
look with a light to see where coolant is leaking from. whatever part is found to be leaking should be changed. If the car may not be worth a proper repair you can try a cooling system sealer to see if it might stop the leak