The huge numbers you're seeing is because you haven't configured the Google Keyword Planner correctly. BSNL is a giant internet service provider in India (which is where the bulk of the searches are from). If you set the Keyword tool to "UK only" you see a much more logical 3,600 searches and "low" advertiser competition, which is shorthand for "nobody cares about this keyword".
A Google search for...
bsnl site:.uk
doesn't turn up any likely buyers in the first few pages of results, which again suggests "nobody cares" since if it matched a key product or company in the UK they'd be there in the top results.