I Need a Help for SEO
 

What are the best way for maintain my website ranked keywords on same position

Agreed with sadianisar, but I want to add some more that ssl , website speed, structured data are main ranking factor so need to look into this.

Keyword ranking can be maintained by good content updates and also by building backlinks from various relevant webpages. Some of the most effective methods are:

Guest posting
Article submission
Press release submission
Social bookmarks
Classified ads
Infographics submission

on page and off page optimization

on page and off page optimization and off page tools
Guest posting
Article submission
Press release submission
Social bookmarks
Classified ads
Infographics submission

Streamline every one of the systems of On-Page and use in the substance.
Make back-connections in high DA destinations utilizing the catchphrases.
Use catchphrases in title, h1 label, alt label, grapple content, content, signature, and so on.

Update the quality content for your blog regularly and also don't ignore the social media marketing.