How its possile without meta keywords?
 

Some of competitors does not using meta keyword and also meta description.
They are using only meta title with limited characters.
But they are having top search results for targeted keywords.
How its possible?

Meta keywords does not play a very important role. The competitors can get ranking to the website using various off page/link building techniques of high page rank.,.

This can be possible with the help of the quality content which help the website to stay in the SERP results, without the met description and meta keywords.

meta keywords is the most important tag for a website so please do not miss this

how abt Tag manager of Google Webmaster tool?

Yes, it is possible without using meta keyword you can rank your website. Just by writing good quality content, off page/link building techniques.

Write quality and interesting content related to your keyword can help you to rank in SERP without meta tag and meta description

Google doesn't use the meta tag keyword for ranking. ... It's just not correct when so called experts write that Google ignores meta tags. ... A: It's possible that Google could use this information in the future, but it's unlikely.

It's also due to your website popularity in SERP, and no of referral links