If you want to learn the concepts, go for Guyton. Best author in term of understanding physiology. If you want to learn more, Boron and Berne and Levy are the alternatives with Ganong. Among the indian authors, Indu Khurana is good. The others have a problem with maintaining the flow of single authorship as most of them just copy paste sentences and paragraphs from different authors although they are informative they lack the easy comprehensibility offered by a sole writer.