During an upgrade process electricity gone and the router went into bootloop.
I have tried several time to reset. But I think it’s not resetting also. 
I connect hex to pc and in “change adapter option” it’s showing frequently (unplugged, identifying and unidentified network ) this error. And I’m unable to find my device in winbox and netinstall.
Model: Mikrotik hEX S (with 1 sfp and 5 ether port)
Plz help me 
When you did netinstall, did you follow instructions for netinstalling ? Are you using windows machine ?
Try to hold reset before applying power.
That way backup bootloader will be used, in case the normal one got corrupt as well.
Netinstall can be quite finicky.
https://help.mikrotik.com/docs/display/ROS/Netinstall
I have a lot more success using a Linux machine.
Put a switch between the PC and RouterBoard.
PC takes too long to ‘bring up’ the network interface and you miss the chance to NetInstall.. Had this happen more than once on different systems.
If you are really stuck and the previous suggestion (backup bootloader) doesn’t work either, there are pads on the board for the serial console you can use to recover the board.. Been there, done that.. Used them fix/recover one I had.