Clamp Meter is not working
I used it to check voltage of mosquito racket


It might be just the battery that needs changing (BAT sign on display) or the several thousand volts on a mosquito racket zapper has zapped your meter. Note that your meter is only rated up to 1000 volts DC.

This Wiki quotes this: -


  The grid of the flyswatter is electrically charged to a voltage of
  between 500 and 1500 volts (V)


This Wiki quotes this about AC powered zappers: -


  A high-voltage power supply powered by mains electricity, which may be
  a simple transformerless voltage multiplier circuit made with diodes
  and capacitors, generates a voltage of 2,000 volts or more, high
  enough to conduct through the body of an insect which bridges the two
  grids, but not high enough to spark across the air gap.