Persons with disabilities (PWDs) who qulify the Civil services exams has to be cleared by the Department of Personnel and Training (DoPT) for suitable services.
In 2012 and 2013, out of 67 such candidates who got selected, few to have to wait for service allocation.
Many selected PWDs are allocated lower services than their ranking in the merit lists on the ground that the nature of their disability prevents them doing the job in most services.
The allocations of services is decided on the basis of the "list of services identified suitable for physically disabled category. This is based on the physical requirements and functional classification" published in the gazette about the service a successful candidate with disability can get.
For instance, under the category of locomotor disability, if the disability affects both hands or arms, you can get into the Indian Administrative Service (IAS) but not any of the other 23 services.
Similarly, the Delhi Andaman and Nicobar Islands Police Service (DANIPS) is open to those with one leg affected or whose hearing is impaired.
However, they are not eligible for either the Pondicherry Police Service or the Indian Police Service (IPS).
All accounts services, the Indian P&T Accounts & Finance Service, Gr.A, Indian Civil Accounts Service, Gr. A and Indian Railway Accounts Service are open someone with one arm (OA) or one leg (OL) affected or with one arm and one leg affected (OAL) and to those with both legs affected (BL). The Indian Audit & Accounts Service Gr. A alone is not open to persons with both legs affected.
There has been a lot of protests due to these perceived discrepancies. A group dedicated to the cause of PWDs is formed. It is called the National Centre for Promotion of Employment for Disabled People (NCPEDP). With much activism they have been able to now get a 3% quota in all services for PWDs mandated by the Disability Act 1995.
Please read more on this here. www.ccdisabilities.nic.in