With the increasing usage of Internet for Income Tax related work including tasks such as applying for PAN and TAN or for filing Income Tax returns, the common problem being faced by many taxpayers and assessees is how to find out their particular Circle/ Ward/ Range in which they need to file return with or are assessed with.
Normally, this information is provided by your advocate or CA but these details are also available on the official websites of the Income Tax department of India.
PAN Application - Applicants can find the Assessing Officer code on the basis of their city and the address (link)
Jurisdiction Details - Enter your PAN number to know the jurisdiction, Area Code, AO Type and Range Code (link)
PAN Details - Enter your full number and date of birth to know your PAN number online (link)
Application Status - Fill in your full name and date of birth to know the current status of your PAN and TAN application (link)
For further details regarding finding out the assessing officer, an interactive guide at incometaxindia.gov. Here one can find their exact details on the basis of their address, income level, sources of income and other parameters.
However, many of the details found on above link are not exhaustive and are incomplete. As such in most likelihood, you will need to visit your local Income Tax Office or your financial adviser.