It totally depends on your knowledge and hard and smart work if you have all this than it will be take near 6 to 7 month but is not an easy task you have to Deap knowledge about Onpage and offpage SEO.

There is no time frame for that and depends upon your work, You have to done with quality work it will come up the good result in your website quickly.

It totally depends on the keywords

I don't believe in 3-6 months because actually there is no certain time on when to rank. If you want to rank focus on your target audience and not just on search engine and optimization alone.