3 month VISA enough to find a job

Hi,

If a person is from a country which is visa-waiver country and it allow him to live 3 months without VISA, are three months enough to find a job and apply for PR or it will took more time then that, he is a telecom engineer, if it will took more time to find job then he will apply for VISA and hopefully he get 6 or 9 month VISA

I know nothing is guaranteed just want peoples opinion.

Take Care