According to the report, India is believed to have added nearly 10 more nuclear warheads to its arsenal, which was estimated at 110-120 in 2016.
The indigenous Agni-V missile, which is India's latest road-mobile, canister-launched ballistic missile with a reported intercontinental range and capability of reaching significant targets in China, also finds mention in the report.
"India is gradually expanding the size of its nuclear weapon stockpile as well as its infrastructure for producing nuclear warheads," the report said while referring to India's decision to build six fast breeder reactors over the next 15 years, which, the it claims, "will significantly increase its capacity to produce plutonium for weapons."
Two of these reactors are expected to be built at Kalpakkam, around 70 kilometres from Chennai while the locations for four others have not been ascertained as yet.
India has so far not released any official figures of its warheads even though it continues to follow the principle of minimum credible deterrent and a no-first use policy, the report added.
The SIPRI report also states that India is currently working on a new unsafeguarded gas centrifuge facility, which, though motivated by its plans to build new naval propulsion reactors, could be used to blend its current plutonium arsenal with uranium secondaries.
The report states that India is highly focussed at developing "the naval component of its triad of nuclear forces in pursuit of an assured second-strike capability" while citing the recent induction of India's first indigenously built nuclear-powered submarine INS Arihant. The submarine, it says, is capable of carrying two-stage 700-kilometre, range SLBM.
"India is also developing a more advanced SLBM that will have a range of up to 3,500 kilometres," the report added.