Now you are making sense. Its true that round-the-clock awareness of the adversary's nuclear arsenal is required prior to conducting a first strike, but in India's case, things are a little different.
First, the majority of the Indian nuclear arsenal is composed of the Air-arm. Second, India has established quite fewer deeply buried missile storage sites. Third, although road-mobile TELs have been developed for the missiles, majority of them are rail-based. Combined with the knowledge obtained by HUMINT, these facts can be taken advantage to conduct a first strike that takes out half of the Indian nuclear arsenal and command and control structure. Now, by no means it is a successful first strike, but it may cripple the Indian SFC to a great extent.
The second-strike capability (SLCM-based) is not yet operational.
P.S. Primitive and Pre-emptive are two different things.