Mumbai, May 5 -- Billionaire Mukesh Ambani's Reliance Industries Limited (RIL) has purchased a triplex apartment on the top three floors of a 17-storey luxury residential building in the Bandra Kurla Complex (BKC) for Rs.120 crore, according to the deal documents accessed by HT via the proptech platform Property Science. The apartment, with a carpet area of 16,128.85 sq ft, is on the 15th-17th floors of wing G at Signature Island, opposite the Sofitel Hotel in BKC. The price per square foot stands at Rs.74,401. According to the deal documents, RIL purchased the apartment from Joinwood Reality Private Limited on April 28. Joinwood Realty had bought the apartment from the developer, Sunteck Realty, in 2021. Sunteck had built Signature Island, comprising duplex and triplex homes, in 2015 on a plot leased from the Mumbai Metropolitan Region Development Authority (MMRDA). The commencement certificate was issued in May 2015, and the Occupation Certificate in November 2015. In 2015, actors Aishwarya Rai Bachchan and Sonam Kapoor had also purchased luxury apartments in the same complex, which has three towers: Signature Island, Signia Isles, and Signia Pearl. Kapoor had bought a flat in Signature Island for about Rs.50,000 per sq ft, while Rai Bachchan had purchased an apartment in Signia Isles for around Rs.38,000 per sq ft. Banker Uday Kotak had also reportedly booked an 11,000 sq ft apartment in the same complex for approximately Rs.55,000 per sq ft in 2015. In February 2025, Kotak set a new national record by paying Rs.2.75 lakh per sq ft for apartments in the Shiv Sagar building at Worli Sea Face. USV Pharmaceuticals chairperson Leena Gandhi Tewari broke this record in May 2025, when she purchased two sea-facing duplex apartments at Naman Xana, an ultra-luxury tower at Worli Sea Face, for Rs.639 crore at Rs.2.83 lakh per sq ft....