TRUE. The British Titanic Inquiry was held at 59 Buckingham Gate, seen on the left of the below photograph:

The original building was designed by John Macvicar Anderson as the headquarters of the 7th (London Scottish) Middlesex Volunteer Rifle Corps and was opened by the Duke of Cambridge in July 1886. From 1899 to 1901 the All England Open Badminton Championships were held in the drill hall. The 7th (London Scottish) Middlesex Volunteer Rifle Corps became the 14th (County of London) Battalion, London Regiment (London Scottish) in 1908.
In May 1912 the drill hall was used as the location for the inquiry into the sinking of RMS Titanic. In August 1914, the 14th (County of London) Battalion was mobilised at the drill hall before being deployed to the Western Front. In 1937, on the break-up of the London Regiment, the unit based at the drill hall was re-designated as The London Scottish, The Gordon Highlanders.
In April 1944, during the Second World War, Princess Elizabeth visited a Sea Scouts exhibition at the drill hall. The drill hall was demolished in 1985 and parts of the structure, including the wrought iron roof, the double-level iron galleries and the war memorials, were relocated to the new Horseferry Road drill hall. The Buckingham Gate site has since been redeveloped for offices.
The Horseferry Road hall can still be seen today. From the outside the building is arguably less remarkable:

But the interior of the Hall can be viewed by appointment and it is still evocative of the Titanic Inquiry:

Inside the building you can still see the wooden war memorial panels, clock and galleries which are evident in the above photograph.
You can also well imagine that giant model of the Titanic in the corner of the Hall, and Bruce Ismay or Edward Wilding or Captain Lord of the Californian answering questions, surrounded by these objects.
If you would like to explore these and other places in London connected with the Titanic, then do take a look at my Titanic London Walking Tour here: https://timmaltin.com/2019/04/11/london-titanic-walking-tour/