I have seen that there are no views for my question about earth-like planets. So I wanted to ask here on meta that whether I can ask question about this or not.
Earth-like is absolutely astronomy, is it on-topic?
Sure - I think it's on topic. There are definitely biological elements to this discussion. Things like "What is the definition of life?", "What range of conditions are conducive for life?", probably fall into that category more so than astronomy. But given then successes of the Kepler mission (Kepler|NASA), detecting exo-solar planetary systems and the study of their atmospheres is absolutely something that the astronomical community is focusing their attention on.
I think you are talking about How do a scientist say that he found an earth like planet. That question is not at all clear to me since it seems to be asking about biology:
My question is, if there are mountains and other similar objects on an earthlike planet, do scientists have an image of life there? Because even plants are living objects. Don't they count plants as living ones?
I was shocked to come to know that scientists call plants living organisms and have included them in a separate Kingdom Planta but when they show a planet, they show a greenish circle, but say there is no life there! Plants can be included in living organisms.
We seem to be missing a fair amount of context here. You mention "a scientist" but you don't say who. Overall, the question doesn't come off as very well thought out, so it's very difficult to provide a useful answer. I previously put it on hold so that you would have an opportunity to edit it before getting more downvotes or unhelpful answers.
But to answer your question: Earthlike planets are certainly ontopic.