Telengana.
Since you have not qualified your question, I am assuming that it is an all out war with India on the other side with every Indian neighbour an enemy or an ally of the enemy.
Since most of North and North Eastern India is easily accessible via land the States there are the most vulnerable. Besides they are bordering the most strong of India’s enemies (as per the assumption, everyone else is an enemy).
That leaves us with just the peninsular States. Given the navies of our enemies are going to target all strategic points where India has a navel presence, almost all the peninsular states with a coastline are going to be targeted. Sri Lanka, our enemy to the South (as per the assumption) is going to make Kerala and Tamil Nadu really vulnerable to attack by providing base to China.
Andhra and Orissa and West Bengal are going to be attacked by Myanmar and Sri Lanka and Bangladesh. Maharashtra and Karnataka and Gujarat and Goa by Pakistan.
All these things leave out Telengana as the safest choice where you can go. It is landlocked. Relatively removed from all land borders and also has a hot, hostile, semi-arid terrain
But unfortunately, there comes a DF-41. Move..Move..Move…Bamm!!!
Nah. There is no place that is actually safe if an all out war breaks out.