Hello AntonioGuimaraes
Seems you asked this question in post here: 2SK 783 replacement
Along with what Adam7 suggested, one of our Apps engineers also replied to you with a list of possible options in link N-Channel Single FETs, MOSFETs | FETs, MOSFETs | Transistors | Electronic Components Distributor DigiKey
Are you having difficulty choosing from one of those options or can you not access the links?