Hi Nand -- this is a 1.5 book.
Review is here:
Website for the book is here:
Due to Joomla's release schedule, I doubt you'll see many books out on Joomla 1.6, which actually will not be supported past August. Joomla 1.7 is due out in July.
Here's a post where I explain the Joomla release process and support going forward:
Oddly, Joomla 1.5 will be supported LONGER than Joomla 1.6 or 1.7.