CBI has sought Red Corner notice against Nirav Modi: What does it mean?

The CBI has asked the Interpol to issue a Red Corner Notice against absconding billionaire jeweller Nirav Modi in the over $2 billion banking scam involving Punjab National Bank.
The red notice is the most commonly used, considering that 12,878 were issued in 2016. The red notice is a request to locate and provisionally arrest an individual pending extradition. It is issued by the General Secretariat at the request of a member country or an international tribunal based on a valid national arrest warrant. It is not an international arrest warrant.
It may be noted that Interpol cannot compel any member country to arrest an individual who is the subject of a Red Notice. Each member country decides for itself what legal value to give a Red Notice within their borders.

An orange notice, 48 of which were issued in 2016 by Interpol, warn of an event, a person, an object or a process representing an imminent threat and danger to persons or property. It is basically used to warn of an impending terrorist threat or attack.

A blue notice is issued to locate, identify or obtain information on a person of interest in a criminal investigation, similar to the one issued by Interpol. There were 4,129 blue notices issued by Interpol in 2016.

A black notice issued for help in identification and information on unidentified bodies. There were 123 black notices by Interpol in 2016.

A green notice is issued to warn about a person's criminal activities if that person is considered to be a possible threat to public safety. It is also issued to provide warnings and intelligence about persons who have committed criminal offences and are likely to repeat these crimes in other countries. In 2016, 930 green notices were issued.

In 2016, Interpol issued 2,675 yellow notices, which are used to locate a missing person, especially minors or kidnapped children or to identify a person unable to identify himself/herself. Yellow notices assist locating a missing person, particularly if there is a possibility that the person might travel, or be taken, abroad. It is also used for children who are victims of parental abductions or unexplained disappearances.

Interpol also issued 106 purple notices in 2016, which seek or provide information on modus operandi, objects, devices and concealment methods used by criminals.