A person needs to live in India for 12 years before they can apply for naturalization as Indian citizen.
Note that neither India not Singapore allow dual citizenship, so applying for Indian citizenship will mean the loss of her Singaporean passport. She should think very carefully before deciding to give up her Singaporean citizenship.
Many people in India would love to have Singaporean citizenship, with all benefits it gives.
Note that India allows citizens of other countries who are born in India or have Indian parents to apply for so-called "Overseas citizenship of India", which allows a person to live and work in India while retaining their original citizenship.
No waiting period is required for that - she just needs to file an application with an Indian embassy and wait for a couple of months.- Dmitri A
It depends on the Issuing Department.
if its post inquiry then it should be issued with in 2 weeks. You will get an acknowledgement message to your phone that it was delivered and its currently posted to your house. or else go to that respective office and check it once, they may delay it because of work load.- ChandraSekhar