AFAIK Trai's guidelines say that number should be ported in 7 days.
Refer to these:
Section 10 in this document:
http://www.trai.gov.in/WriteReadData/trai/upload/Regulations/89/Regulation23sep09.pdf
Amended by:
Point 4 in this document
http://www.trai.gov.in/WriteReadData/trai/upload/Regulations/97/MNP_Regulation24nov10.pdf
Hope it will be of some help.
Refer to these:
Section 10 in this document:
http://www.trai.gov.in/WriteReadData/trai/upload/Regulations/89/Regulation23sep09.pdf
Amended by:
Point 4 in this document
http://www.trai.gov.in/WriteReadData/trai/upload/Regulations/97/MNP_Regulation24nov10.pdf
Hope it will be of some help.