From ROC website you can get Date of Incorporation. Then by mentioning name and date of incorporation you can get the PAN no of that company from income tax website.
06 July 2011
Unless you have full particulars you cannot find any details of PAN Number of the concerned company. If you have good connection in the Income Tax Department you can get all the details only from the Income Tax Site which is not available publicly. This site is used only by the Income Tax Department, their officers and subordinates.