Well I can tell you that its a Queen Elizabeth II Silver Jubilee coin celebrating 25 years since her coronation. Not sure on the value but the denomination is one crown, set at 25 New Pence since the Crown is obsolete.
Welcome to the forum amardeep. The Standard Catalog of World Coins by Krause and Mishler lists your coin as KM#920, a copper-nickle 25 New Pence commemorating Queen Elizabeth II's Silver Jubilee. In the 2005 32d Ed. it is retail valued at only 65¢ in Extra Fine condition ($1.50 uncirculated). I'm afraid that with a face value in U.S. currency of just a tad under 59¢ at today's exchange rate, one like yours, which would probably grade no better than Very Good, doesn't really have a numismatic value.