I have paypal business account. i want to use this business account for 3 shopping cart? can i use same paypal business account for my 3 shopping cart. if yes then once user payout from my site via paypal then can i redirect my page on my home page or thank you page? for redirect the url i have to any setting in business account?
If you are talking about shopping carts, are you talking about three different websites? With a business account you can do this, however you have to let PayPal know that you are going to do it. The best account is Website Payments Pro, where if you have a site the PayPal account is in the background and the customer doesn't know you have a PayPal account. The redirects have to be approved by PayPal or they can suspend your account temporarily.
When you create the checkout button, you have the option of giving an url of your website where you want the buyer to be redirected after payments. The other form is to use the direct payment app provided by paypal, through this you can get the visitors to pay from within your site, though this might require some technical knowledge or you can get a developer to do this for you, else you can do it yourself if you go through paypal developer site