Yes, you can file an RTI BBMP asking about the current status of your property tax.
Municipal Board were formed under the Improvement of Towns Act of 1850. Later, a similar Municipal Board was also formed in the Cantonment area of the city. The two boards were legalized in 1881, and functioned as two independent bodies called the Bangalore City Municipality and the Bangalore Civil and Military Station Municipality.
In January 2007, the Karnataka Government issued a notification to merge the areas under existing Bangalore Mahanagara Palike with seven City municipal council (CMC)'s, one Town municipal council (TMC) and 111 villages around the city to form a single administrative body, Bruhat Bangalore Mahanagara Palike.
Hence it is a public authority under section 2(h) of the RTI Act 2005.
For further assistance to file RTI application to any PIO please refer https://onlinerti.com/how-to-file-rti-online-for-karnataka