ISIN is a code, which is the short form for International Securities Identification Number.
Each ISIN is country specific which identifies a particular security, such as stocks (equity and preference shares), bonds, options and futures, commercial paper, warrants etc issued by an organisation.
It is an international numbering system set up by the International Organization for Standardization (ISO).
The structure of ISIN is defined in ISO 6166. ISIN comprises of both alphabets and numbers.
1. First two letters - Country code ( The country code is the ISO 3166-1 alpha-2 code for the country of issue, which is not necessarily the country where the issuing company is situated.)
2. Next nine alpha-numeric digits - the National Securities Identifying Number (NSIN), which identifies the security.
3. Last Numeric Digit - Check Digit (used for preventing errors)
For searching the ISIN of any organisation, check out the below link:
Example: ISINs for RELIANCE CAPITAL ASSET MGMT LTD - INF733I01010 & INF733I01028