Explanation:

• According to the recently released ‘EnviStats India-2024’ report, the Nagarjuna Sagar-Srisailam Tiger Reserve (NSTR) has been ranked first among India’s 55 tiger reserves for its leopard population, with an estimated 360 leopards. 

About Nagarjunsagar-Srisailam Tiger Reserve (NSTR)

• Location: It is located in the Nallamala hill ranges (an offshoot of the Eastern Ghats) of Andhra Pradesh.

• This is the largest tiger reserve in the country, spreading over an area of 5937 sq. km.

• It hosts the largest tiger population in the Eastern Ghat landscape.

• It is named after two major dams in the area, Nagarjuna Sagar Dam and Srisailam Dam.

• Two wildlife sanctuaries, namely Rajiv Gandhi Wildlife Sanctuary and Gundla Brahmeswaram Wildlife Sanctuary (GBM), constitute the NSTR.

• The river Krishna traverses through this reserve for a linear distance of around 270 kilometers.  

Hence option 3rd is correct.