The driver seat belt light keeps flashing on dahsboard.
When I pull seat belt little more (say 2 feet extra) light goes OFF.
I guess the seatbelt sensor is bad.
2000 corolla.
Sounds to me like you localized the problem. I would imagine the switch that gets depressed when you stick the buckle in, is defective or become misaligned. The other possibility is that the wiring inside or outside the latch is somehow damaged. If it were me, I’d get one from a junkyard/ebay and either take it to a mechanic or diy, depending on your level of comfort with repairing the problem. Best of luck!
I had a similar problem with a 2005 Honda Accord. I checked around on line, and an inexpensive fix might be to clean the buckle mechanism. You have to pull the cover off the buckle and brush or vacuum the inside to clean years of debris away. Getting at the back of the buckle can be difficult because there is very little room. If it works, it only costs your time to do it.
There is a good chance that your Toyota and my Honda bought the belts from the same manufacturer. The car manufacturers don’t make the belts themselves. BTW, my belts were not Takata.