Sometimes you can unthread the drain from the tub side, and recaulk.
If the leak is beyond that point, then you may have to explore.
Do ya'll know of an easy way to seal the drain beneath my jacuzzi tub without ripping out tile, walls, etc. Can I caulk from the top? Someone told me that the only way to reach the leak (which is about 3 feet out of reach)was to rip out the ceiling beneath the tub or go thru the adjoining shower wall. Thanks!