This book is only available in the central libary of India which don't have any policy of inter-library loan. So, if google has scanned it why not give it to download ?
Now, why wouldn't the original copyright holder waive the rights? I'm guessing that, since the title seems to have been published by a local government, for purely bureaucratic reasons rather than ones of ideology.
Are there really no other libraries that have it? I'd be shocked if it's not in the Library of Congress, the British Library, or Widener.