yes
Mr. G.Srinivasan is the Chairman of GIPSA
Dear Sirs or Sirs "Mr. and Mr." appear to be plural. In that case the term is "Messrs." Otherwise you can say "Mr. X and Mr. Y."
Mr. L. N. Dhamani - Chairman Mr. Amit Dhamani - CEO Mr. L. N. Dhamani - Chairman Mr. Amit Dhamani - CEO
Oh dear:Hyvänen aikaDarling/Dear:RakasDear mr...:Hyvä herra...
Mr. Shailesh Singh Chairman DGFT
Dear Mr. Capote was created in 1983.
Dear Mr. Prohack was created in 1949.
Mr. President
Dear Mr. Henshaw was published in 1983.
Dear Mr. Wonderful was created in 1982.
Dear Mr. Fantasy was created in 1967-12.