By 2027 Japan plan to open their first Maglev section Tokya-Nagoya (350km), then only they will come to know about the actual efficacy of their maglev train.
India don't have the funds for extremely costly Maglev, it will be dependent on the Maglev train project contractor to fund it.
It would not be wise for Japan to make heavy investment in Indian Maglev project before they are themselves damn sure about actual performance of Maglevs on commercial run.