Samsung Metro XL does have 128 MB internal memory.
No. You cannot use Jio sim card in this phone.
No. Samsung Metro XL does not have WiFi.
Yes, Samsung Metro XL supports the Hindi language.
You can store up to 1000 contacts in Metro XL. In addition, you can store up to 250 contacts in each of your sim card. So, if you are using 2 sim cards, in total you can store up to 1500 contacts.