@Geethesh I've seen your battery specifications. The battery you are using gives out 3V which is a nominal voltage but you must take one more parameter into consideration while choosing a battery for your applications. It is nothing but Amperage that it can supply.
I will explain "WHY?" ampere rating is so important in your application. HC-05 module draws most of the power from the battery while transmitting the packet data, it almost draws 200mA of current at a voltage of 3.3V this means the battery you are going to use must supply current at this amounts. But if we see the battery that you have to use i.e CR2032 which is a coin cell battery, its maximum supply current is just 3mA but our minimum required supply current is 200-250mA which is way too high for the battery to supply and that is the reason of your failure.
So, please use these battery types of Li-Ion batteries which can give a high supply current of order 500-700mA at 3.7V. I've been thinking that you are using these since the start of our conversation and that lead to my misunderstanding and made the correct reply late. Sorry for the delay. All the best...!!