Scrape Data from Website using css style Using Beautifull soup

To get the coupon code, I would not rely on the color style attribute. Instead, get the next element to the Coupon Code text:

soup.find(text=lambda x: x and x.startswith('Coupon Code')).next_element.text

Demo:

>>> from bs4 import BeautifulSoup
>>> 
>>> data = """
... <h6><span style="color: #808000">25% Cashback on Recharges :</span></h6>
... <ul>
... <li>Get 25% Cashback upto Rs.25 per transaction.</li>
... <li>Coupon Code : <span style="color: #ff0000"><strong>AXISCB50</strong></span></li>
... <li>Maximum 2 transaction per Debit/Credit card.</li>
... </ul>
... """
>>> 
>>> soup = BeautifulSoup(data)
>>> 
>>> print soup.find(text=lambda x: x.startswith('Coupon Code')).next_element.text
AXISCB50

Some coupons are displayed via ajax which is displayed only once we click the button.How will i scrape_ these data which is displayed via script?

You would need to research what requests are sent when you click a button. Use browser developer tools, Network tab. Then, simulate the request(s) in your python code. requests is usually a good choice.