Hello Dipak Chatterjee,
You can earn handsome amount of money from this website per month depending on your contribution. To sale your Coins; I suggest you to Post Classified Ad in BengalSpider with your requirement.
As, Mr. Mohan suggested, you should use normal writing format and don't use unnecessary Capital Letters.
Point and Cash is not the same here in BengalSpider - Points is to determine Member's Level and Rank. Only higher than Gold Level members can apply for Adsense through BengalSpider and Gold Level membership can be achieved only by accumulating Points. In every section of BengalSpider you can collect points (like Voting in Poll, Joining Community, Posting Picture etc); But in few sections of BengalSpider you are eligible to get Cash and when you reach Rs.1000/- then the Payment will be made.