You can claim easmentary right of necessity if there is no other access to your land 

2)Section 13 of the Indian Easements Act deals with easement of necessity An easement of necessity means an easement without which the property cannot be used at all. Mere convenience is not the test of an easement of necessity. It can be claimed only when there is absolute necessity for it, i.e. when the property cannot be used at all without the easement and not merely where it is necessary for its reasonable, or more convenient enjoyment. A  man cannot acquire a right of way as an easement of necessity, if he has any other means of access to his land however more inconvenient it may be than be passing over his neighbours.

3) under section 35 of easement act you can obtain permanent injunction restraining your neighbour from obstructing your right of passage . pending hearing and final disposal of suit you can claim interim reliefs .

It is immaterial whether land is agricultural land or not 

You can file a suit for easement rights for road access from your land.

Before that you can talk to your neighbor and try to buy a part of land by registered sale deed for pathway to road access. 

If he is not willing to sell the part of his land for pathway purpose then you can file a suit for easement rights by necessity. 

Since you have been using this land for almost five decades and you have evidences to prove this as your pathway to road access from your land,  you can claim easement rights through court of law. 

You can consult a local advocate and proceed as suggested. 

You need to file a petition under easement Act for seeking access to your land through their lands

In your case, you need to place an application before the civil court claiming your easement rights on the property of your neighbour. As you have mentioned that the land of your neighbour is converted to industrial land, a memorandum of understanding executed by and between you and your neighbour seeking permission to pass through his land in order to have an access to your land would be person specific and a temporary relief. Hence it is advisable for you to approach the civil court claiming your easement rights and place your proposal for payment therein and seek order from the civil court stating applicability of the same to their successors, assignees, and all subsequent transfers.

There is no such rule that path should be given ,but either it is customary or easementary right.In case when one is using road from the land of neighbour and if that neighbour closes that road,the user may approach to the Mamlatdar under Mamlatdar's Court Act for restoring the use