Ripe fruit or grain is fully grown and ready to eat.

If a situation is ripe for a particular development or event, you mean that development or event is likely to happen soon.

If someone lives to a ripe old age, they live until they are very old.

If something is ripe for picking or ripe for plucking, it will be very easy to obtain.

If you say the time is ripe, you mean that a suitable time has arrived for something to be done.