Well you can use the Google toolbar to get your pagerank, but there's a lot of debate as to how accurate this is and whether it's just old info. I would also suggest signing up for Google Sitemaps because they give you a lot of information about how well (or not well) you're indexed in Google. They're not just sitemaps

I don't recommed any 3rd part tool to check rankings in google as there are chances of getting banned in google for using it without proper API

I got 100s of my websites banned for the same reason. So do not try and get hurted

Google will not ban websites that check their ranking without using their API. That's just a myth. If it were true all you would need to do to get your competitors banned is constantly check their rankings with these tools. The worst thing that can happen if you use these tools is that Google blocks your IP so you can't query their servers anymore.

But I should also add it is a good idea to use their API as that is what it is there for.