A trust is an agreement between people (Settlor and Trustees) to manage property over which they have control either to benefit other people (called beneficiaries) or for charitable purposes.

Any person competent to contract can create a trust. A Trust can also be formed on behalf of a minor with the permission of civil court.

A trustee can be any person that is, an individual or a corporate body or corporate sole, capable of holding property and competent to contract. What is a private trust

A trust which is created is for the benefit of general public is a public trust. Generally a public trust is created for setting up of charitable and religious purposes, schools, colleges, other educational initiatives, hospital, old age homes, orphanage, for promotion of child health and their empowerment, welfare of weaker section of society, and for fulfillment of Corporate Social Responsibilities (CSR) by companies under section 135 of the Companies Act, 2013.

There is no upper limit for the trustees but a minimum of two trustees are required for registering a Trust.

A trustee who has accepted the trust cannot afterwards renounce it except with the permission of the principal civil court of original jurisdiction or if the beneficiary is competent to contract, with his consent or by virtue of special power in the instrument.

There are no privileges and tax benefits available for the private trusts but public trusts can always avail tax exemptions by registering with the income tax department.

A trust created by will can be revoked at the pleasure of the testator.
A trust otherwise created can be revoked only by the consent of all the beneficiaries who are competent to contract.

Yes, amendment can be made by a rectification or supplementary deed.