Please when i press next to active the apple pay cart they telling me that the region can not be able to use it with apple pay why ?

See the following Apple articles:

Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

Countries and regions that support Apple Pay

Countries and regions that support Apple Pay - Apple Support (EG)

See also -> About billing for Apple subscriptions and media products in India

About billing for Apple subscriptions and media products in India - Apple Support

India

•           Apple ID balance (from adding funds)

•           Net Banking (adding funds only)

•           UPI (adding funds only)

You can use / pay with your Apple ID balance, see the following Apple articles: 

Add money to your Apple ID balance

Add money to your Apple ID balance - Apple Support (IN)