1. All the shareholders can mutually decide to relinquish their rights in the property in favor of one among them. After that they can execute a registered release deed relinquishing their rights in the property.
If one or all the others are not able to travel to India to execute this registered release deed, they can choose a close relative back in India to whom they can entrust the task of executing the registered release deed on their behalf by appointing the chosen relative to be their power of attorney agent while authorising this power agent to carry out the said task on their behalf.
They can execute a power of attorney deed fro their countries of residence duly notarised by a local notary public or duly attested by an Official of Indian embassy and send it to the chosen power agent by a sealed cover, who will then get the same adjudicated before the concerned registrar and would execute the desired document in favor of the chosen shareholder.
2. There is no question of giving NOC to relinquish your rights in the immovable properties, it has to be released only by executing a registered release deed.
3. You people have to obtain legal heirship certificate by applying for one jointly before the concerned revenue department containing/mentioning the list of legal heirs to succeed to the estates of the deceased who is reported to have died intestate.
4. It may take at least a month or more.
5. Read the first answer above.