Which GSM band is best?

GSM is a second-generation (2G ) standard employing time-division multiple-access (TDMA) spectrum-sharing, issued by the European Telecommunications Standards Institute (ETSI).

Reliance Jio uses Bands 3(1800MHz FDD), 5(850MHz FDD) and 40(2300MHz TDD) . Band 40 provides better bandwidth and band 5 provides coverage in remote/rural areas as well as indoors where higher frequency signals cannot penetrate.

Currently in INDIA, 4G LTE band-40 having 2300 to 2400 MHz (TD-LTE) frequency range is active (online) and offered by the operators in indian territory. The other LTE band in 1800 MHz (FDD-LTE) frequency is also auctioned by the INDIA government.