Hi Yogesh,
I'd recommend making use of the TRACe:POINt 1000 (setup buffer size of 1000 points) command paired with the TRACe:CONTrol:FEED NEXT command. You'd then use the TRACe:DATA? query to retrieve all data stored in the buffer. This will setup the 6514 to have a 1000-point buffer size and fill until all 1000 points are full. Then, TRACE:DATA? will print the buffer in its entirety. See section 8 in the instruction's manual for more information.
Model 6514 System Electrometer Instruction Manual | Tektronix
If you want to run multiple iterations of the test, you'd need to clear the buffer between runs (TRACe:CLEar) after you print the currently populated buffer.