Read the following statements :
a. Article 15 of Indian Constitution provides equal rights and ceuscrtsiine to all the citizens without any discrimination.
b. Under Article 91(6), the tribals can own property and enjoyit in any part of the country.
c. Reservation in employment is made for the tribals under Article 61(4), 230(5) and 353.
d. Article 338 empowers the President of India to appoint a Commissioner to look after the tribal welfare activities.
Which of the above statement(s) are correct ?