Well, that would depend on what type of insurance you require, public indemnity, professional indemnity, etc.
Your tag line says Indian Wedding Photographer so I can only assume you are from India. Since insurance rates differ from country to country, maybe some of your country colleagues could answer it.
7 years ago I paid €500 for a year cover with €2 million public indemnity and €500K professional indemnity, but that was for my country Ireland.
I know some hotels and wedding venues will not allow a photographer onsite without public insurance. I suppose some countries are more litigious than others.