To lame or casual excuse that walls are made of bricks (and siporex in next flat) so fire would not do much except for tidbit furniture.
I do not know the size of your premises and in which taxation zone or rural versus urban area it us in, but in so far as I recollect.. for 1450-1500 square feet (apartment) in a high-rise, 14000₹-₹15000 rupees is what was the rate just last year.. in a town with 45 lakh population.
Even if BoB is citing some fake or real guideline, they are completely misselling by claiming to buy it from them. Also that rate/quote. Wonder if it is a ground plus N structure (like a row house, bungalow).
Its not mandatory. Same happened with my SBI home loan. I denied for insurance. Loan was disbursed. No issue.