In Jain tradition, the Chandkaushik snake-bite incident happened during Bhagwan Mahavir’s 12 years of severe austerities, after he took diksha at age 30 and before he attained keval-jnan at age 42. So his age at that event was roughly between 30 and 42, but the texts do not always give one exact fixed age for the bite itself. ( jainknowledge.com)