NEW YORK, May 30 (Reuters) - The fund run by Bill Gross, which dropped more than 3 percent on Tuesday alone, plunged to last in its peer category so far this year, according to Lipper data on Wednesday. Gross' $2.1 billion Janus Henderson Global Unconstrained Bond Fund is now down 6 percent this year, the research service's data showed. Gross, once considered the "Bond King" of Wall Street, co-founded Newport Beach, California-based Pacific Investment Management Co in 1971 but left abruptly in 2014 and moved over to Janus.