Tee,
You should have a professional inspect for the area and cause of leak, and have it properly repaired. You may need to have the vehicle towed as to not cause further damage.
Hello Tee- it really depends on the source of the leak- transmission pan gaskets are easy & inexpensively replaced- the other source of leakage is usually seals- all these except the convertor seal are relatively easy to access & the parts are not expensive- however if the leak is from the torque convertor seal this requires removal of the engine or transmission from the vehicle & can be very expensive - use of Stop Leak additives are not recommended as they may damage other transmission components - hope this helps- thanks Super Girls Auto.