There is confusion between the two. I could get the keys at Two new critically endangered species of Hippeastrum (Amaryllidaceae) from the Brazilian Cerrado
7. Flowers generally campanulate; apex of the tepals salmon or orange, rarely pink, yellowish to green adaxially at their base and forming a circular pattern at the throat ......H. puniceum
–. Flowers infundibuliform; apex of the tepals dark red to carmine, greenish white adaxially at the base with extensions to the middle of the limb ........H. reginae
Both species are reported from India as per details at
Still it appears an uphill task to decipher it.