I am working on Impatiens of Western Ghats, that why I know the number one is Genus Impatiens of family Balsaminaceae. At present, in India there are about 215 species of Impatiens recorded so far, of which 142 species are endemic, and the diversity occurs in two regions, viz. the Eastern Himalayas and the Western Ghats. For others you may search the link given by Dr. Arvind.
Number of Impatiens species in India is probably even higher, 230 or more, but exact number of species is difficult to count, due to synonyms and unresolved taxonomic problems. This number will be growing rather quickly - only in 2016 seven new species of Impatiens were published from India.