how far from my ETS date should I start to apply for job?

It never hurts to start networking and working angles so you hit the ground running after leaving the service.
From the options you stated, I would go with 90 days prior to Terminal Leave. That gives you some cushion to make transitions. Law enforcement positions are kind of fickle, so getting some idea of what to expect and how to shape your resume now are good investments of your time.

You need to contact whichever LE agency you want to work for and find out what their hiring pipeline looks like. Some agencies take like 2 years. I sent a guy home on pass to an entrance exam 16 months before his ETS date. Just make sure the agency knows when are actually able to fill the position.

Where are you looking...Henderson Nv is hiring

Immediately....your new job can delay entry but your ets date cannot

SPC (Join to see) note that if you can get hired earlier than your ETS date that you can get an early release but only approved by BDE.

I had a job lined up 90 days prior to getting out. A lot depends on where you are going to settle down, what type of work/career you going for and what the job market is like in that area.

Start networking now and leverage friends and leaders you know who are now civilians. Networking is hands down the best method to land a job ..... and it’s not begging or charity.

You might be able to make a connection that lines you up with an opportunity or keep you in mind. They can also help you meet others.

The Interview process timeframe is variable based on urgency. But I’d say that you should be prepared to go through a series of opportunities and associated interviews before landing something.

And take advantage of the transitional programs in and outside the military set up by and for vets. Again, it’s not charity. And you are changing your career and culture. You’re the F-ing New Guy, so put on your humble suit and leverage help early and quick.

I wouldn't (and didn't) leave the military without a job lined up. Being an Army Brat and a Career military guy, I had no home other than the military. As I told my supervisory Chaplain, I wouldn't leave without having a place to go. I knew guys who ETS'd and went to their home-of-record, and then looked for a job. Most didn't get what they hoped for. I went where the work was. In my case, I found a church that wanted me as their Pastor, and then put in my paperwork. And it worked out very well.

It's all about timing for the position. Most units will not let someone who is ETSing get out sooner than 30 or 45 days before their ETS date. I know SFLTAP does internships but your commander still has to approve it. Most units still have you on their books and honestly you are holding a slot and every day your in the service but not fulfilling your MOS duties you are preventing them from receiving a replacement for you. Units most times do what's best for the organization and not you specifically. Whatever the case explain your situation to your employer and hopefully they work with you. Law enforcement jobs are a very lengthy process from what I've seen. I've seen guys have to take leave to do it. Goodluck!

Rule of thumb is to allow one month for every 10k you want to make.