Unable to download Apps

Hi Abhi1976,

Welcome to the Apple Community, where some of us do our best to help each other.

Wondering if you tried logged in to the App Store with your Apple ID ?

Your Apple ID is the account to use for adding a payment method to use for everything Apple.

including iTunes, App Store, iCloud, subscriptions etc.

It seems Apple require you to have a payment method in your Apple ID for the first time you use iTunes and the App Store, even if you are downloading a free (Get) App.

The links below are to Apple Support articles, that can guide you, if you wish.

First: Check the payment methods that you can use with your Apple ID:

(Scroll down to see the various countries listed)

https://support.apple.com/en-us/HT202631

Then:

How to create your Apple ID if you do not have one::

https://support.apple.com/en-au/HT204316/

OR 

if you do have an Apple ID account :

Apple ID Log-in:

https://appleid.apple.com

Now you can:

Change, Add or Remove Apple ID Payment methods

https://support.apple.com/en-us/HT201266

After you have used your Apple ID in the App Store and iTunes for the first time,

seems it is possible to remove the payment method, if you wish:

How to remove payment methods from your Apple ID.

https://support.apple.com/en-us/HT204034

or

If you can't remove your last payment method or use no payment method with your Apple ID

https://support.apple.com/en-au/HT203905

Hope this helps you :(