Quoting some details from here
The Academy honours Indian and Foreign nationals who are elected by "peer" committees in recognition of their personal achievements in "Engineering" which are of exceptional merit and demonstrated distinctive eminence in the new and developing fields of technology.
The election to the Academy is by invitation only. Upto 50 Fellows from Academia, R&D and Industry may be elected from the nominations made by Fellows of INAE affiliated to the following Engineering Sections. Under the Rules & Regulations of the Academy, the total number of Fellows at any one time may not exceed 800