Looking to bring my brother in law here to work and hopefully immigrate after, does anyone know of a reliable agency in Philippines or here in Canada that can help?
Unfortunately any jobs offered through agencies are generally scams. I would avoid agencies completely.
If he wants to try to secure a job in Canada, he should apply for jobs with employers directly (e.g. apply for jobs directly through the websites of large companies that are in his area of work).
He should be aware that it will likely be extremely difficult / next to impossible to secure a job. Employers have to go through a very long and expensive process in order to get approval for an LMIA (which is needed in order for your brother in law to apply for a work permit). As a first step, they have to advertise the job for at least a month to prove no Canadian could be found for the job. This is especially difficult to prove right now given all of the COVID-19 related job losses and all of the Canadians looking for work. For this reasons, it's super difficult / next to impossible to find employers willing to go through the LMIA process.
His best option would be to qualify to immigrate through an economic immigration program like Express Entry without having a job offer in Canada.