Does anyone here knows what is the equivalent circuit in gates of negative edge triggered jk flip flop? Thanks

 

Find a positive edge-triggered J-K flip-flop and invert the CLOCK input?

Do you need a master-slave J-K or a non-master-slave J-K flip-flop?

 

Do you know how to use search engines or read datasheets?

 

NPN transistor with a pull up resistor on the collector connected to V+. Simple inverter.

 

The one with preset and reset

 

 

I was going to suggest looking in an older digital IC book, back when the functional equivalent circuits were published. But Mister Chips did a better job than that.