For example if I've page title as "Income tax forms 2012" it should change automatically change to "Income tax forms 2013" in Y2013.
Tokens work for node body but not in title. It did not work when I tried.
Any suggestions?
If these titles are on nodes, and you have the Auto Node Title module installed, you should be able to use [yyyy] for the current year in the replacement patterns section. However, drupal won't automagically go and redo the title for you, but rather, you will have to resave it "next year" for it to take effect.
In addition to Jimajamma's answer, you could use Automatic Nodetitles in conjunction with Scheduling part of Rules. This will allow you to create a Rule which re-saves the particular node at the start of every year, which will update the node title.