Postal Index Number Code

A Postal Index Number or PIN or Pincode is the post office numbering or post code system used by India Post, the Indian postal administration. PIN stands for Postal Index Number and the code is 6 digits long. The PIN was introduced on August 15, 1972.

There are nine PIN zones in India, including eight regional zones and one functional zone. The first digit of the PIN code indicates the region in which a given post office falls in. The second digit indicates the sub-region, and the third digit indicates the sorting district within the region. The final three digits are assigned to individual post offices.

The nine PIN zones cover the Indian states and union territories as follows:

1 - Delhi, Haryana, Punjab, Himachal Pradesh, Jammu & Kashmir(including Pakistan-administered Kashmir), Chandigarh
2 - Uttar Pradesh, Uttarakhand
3 - Rajasthan, Gujarat, Daman and Diu, Dadra & Nagar Haveli
4 - Goa, Maharashtra, Madhya Pradesh, Chattisgarh
5 - Andhra Pradesh, Karnataka
6 - Tamil Nadu, Kerala, Pondicherry, Lakshadweep
7 - Orissa, West Bengal, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Andaman & Nicobar Islands
8 - Bihar, Jharkhand
9 - Army Post office(APO) and Field Post office(FPO)

First 2/3 Digits of PIN	Postal Circle
11	Delhi
12 and 13	Haryana
14 to 15	Punjab
16	Chandigarh
17	Himachal Pradesh
18 to 19	Jammu & Kashmir
20 to 28	Uttar Pradesh/Uttrakhand
30 to 34	Rajasthan
36 to 39	Gujarat
40	Goa
40 to 44	Maharastra
45 to 48	Madhya Pradesh
49	Chattisgarh
50 to 53	Andhra Pradesh
56 to 59	Karnataka
60 to 64	Tamil Nadu
67 to 69	Kerala
682	Lakshadweep (Islands)
70 to 74	West Bengal
744	Andaman & Nicobar Islands
75 to 77	Orissa
78	Assam
79	Arunachal Pradesh
793, 794, 783123	Meghalaya
795	Manipur
796	Mizoram
799	Tripura
80 to 85	Bihar and Jharkhand

Source : http://en.wikipedia.org/wiki/Postal_Index_Number