Q. Can one to avoid giving a handshake to a woman, bow slightly with palms together, as Hindu and Buddhist do (namaste greeting)?
A. We do find that Avraham Avinu greeted the B'nei Cheiss more profusely (24: 7) And Avraham arose and prostrated himself to the people of the land, to the sons of Cheiss.
Horav Shlomo Miller's Shlit'a opinion is that the Namaste greeting, since commonly done by all in those countries, does not carry in our days any religious connotation. Namaste translates as bowing down.
The Rov also related a similar case when Horav Eliezer Silver zt'l met with the former first lady Mrs. Eleanor Roosevelt and she extended her hand to greet him. He quickly reacted by taking off his hat and bowing to her, thus elegantly avoiding a handshake.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a