Am I eligible to apply for the IAS after degree from Open University?????

Yes, you are eligible to apply for the IAS after degree from Open University, provided your university should be approved from DEC which stands for distance education council.

IAS is the Indian Administrative services and the examination for it is conducted by the UPSC in the category of civil services examinations. Following are the details of this examination:

Nationality:
A candidate must be a citizen of:
A subject of Nepal, or
A citizen of India, or
A subject of Bhutan, or
A Tibetan refugee who came over to India before 1st January, 1962 with the intention of permanently settling in India, or
a person of Indian origin who has migrated from Pakistan, Sri Lanka, Burma, East African countries of Kenya, Uganda, the United Republic of Tanzania, Zambia, Malawi, Zaire, Ethiopia and Vietnam with the intention of permanently settling in India.

Required qualification:
The candidate must hold a degree of any of Universities incorporated by an Act of the Central or State Legislature in India

Age Limits
Candidate must have attained the age of 21 years and must not have attained the age of 30 years on 1st August