why my blog is not showing for my brand name search in google?

It should happen rather quickly if your brand has a distinctive name. If you were selling blue bowling balls and the brand was something like "Blue Demon" with a domain name like BlueDemonBowlingBalls.com, a GOOD link or two and some decent content is all it should take. (By "good" backlinks, I'm not talking about the easy to get, horrible links that so many uninformed people here at WF seem to think work. I'm talking about ones that a real person at another site has to place on that site that you do not have control over.)

BUT, if your "brand" is something really generic like "bluebowlingball.com" you may never show up for it without a ton of high authority backlinks because there are simply too many dominant players with far more authority than your site has that sell blue bowling balls (Amazon, bowlingball.com, Brunswick, Dick's Sporting Goods, etc.). "Blue" is not a brand name; it is a descriptive word that anyone might use.

Oh, and the frequency that you publish is totally unimportant unless you are running a news site. It's better to publish one stellar piece a month that real people want to link to than three ho-hum pieces a day that nobody cares about. Every piece of content you create should have one goal only - to be so good that people will want to link to it because the content is helpful to the readers of their blogs. Stop trying to create content that you think is good and that readers of your blog will enjoy (99% of them have no website of their own to link to you from) and start creating content that people with actual websites will want to link to. Develop relationships with those other bloggers in similar niches - that's where real links come from!

I don't know where you are searching from or on what, but both MOZ and SEL show up as the #1 result when I search with just their name.

If your manager is concerned because the main domain name is showing up as the search result instead of the blog when you just search for the company name, he is an idiot.