Will my phone work in the islands with mobile network issues?

I intend to visit Andaman and I am concerned that I will not be able to be in touch with my family and friends back home. The mobile network has been said to be very patchy in the islands. I have been doing some research on the topic of Andaman Tour Packages from Kolkata and I discovered that most of them include SIM cards or portable Wi-Fi hotspots. The network is generally predominant in the city centers, but patchy in the more rural regions. I also read that the internet in the hotels and resorts is usually slow and ineffective, so I will buy a local SIM card or hire a portable Wi-Fi hotspot. The price of a SIM card or a Wi-Fi hotspot will be between 500 and 1,000 rupees, depending on the provider and the data limit. I will keep in touch with my family members back home, which means that I will be ready to spend slightly more to have a good connection.