An Indian man accused of plotting to assassinate a Sikh separatist on US soil is expected to appear in a New York court on Monday on murder charges.Nikhil Gupta was extradited to the US over the weekend after he was arrested last year in the Czech Republic.He is charged by US authorities with trying to hire a hitman to assassinate Sikh separatist leader Gurpatwant Singh Pannun, a dual US-Canadian citizen.US prosecutors allege Mr Gupta was directed by an unnamed Indian government official. India denies having anything to do with the alleged plot.Last month, the Czech Constitutional Court…