Can i use mother's caste?

You can choose the of either of your parents. 

But for the purpose of availing the benefits under OBC NCL category,  generally father's caste is taken into consideration. 

my father was died on 03/09/2009. Can I make obc certificate of mine with the help of mother's certificate? I am the main earning person of my family

Only the father's caste will be the caste of the children.

What is the supreme court judgement regarding this subject?

only cast of father will prevail.

Those who say father's caste are also wrong. The question  of eligility to avail reservation by children of inter-caste marriages has been considered by several High Courts and the Supreme Court. One Judgment by the Supreme Court says that if the child continues to suffer the disabilities of the lower caste he or she will be eligible for the reservation. Now who is to find out whether the child suffers from disabilities? What are the disabilities of the lower caste? These are only vote back politics. Generally a low level officer issues caste certificate according to his whims, fancies and prejudices. Generally bribing him helps.

now what should i do?

Meet the officer who should give you the caste certificate and try. I wish you good luck.

The general principle is that the child belongs to the father's caste. However, if the child has been brought up in the mother's community, he/she could be taken to be belonging to the mother's caste and a community certificate to this effect could be applied for placing the relevant facts on record.

The Govt  insturction are very clear on the subject.

According to ancient Hindu practice inter-caste marriages were of 2 types. If father belonged to a higher caste and mother a lower caste it was called an anuloma marriage. If the father belonged to lower caste and the mother to a higher caste it was called a pratiloma marriage. Under anuloma the child belonged to mother's caste not fathers caste. Some 50 years back the Namboothiri Brahmins of Keralam used to marry Nair women of lower caste. Their children were considered to be Nairs, the mother's caste. In Pratiloma marriage the child belonged to a caste lower than that of father.  Yayati was Kshatriya and he married Devayani a Brahmin. Their son was Yadu. He was not a Kshatrya. The descendants of Yadu are called Yadavas.  Yadavas are OBC eligible for reservation. I have stated only what is in scripttures, not my personal opinion.

Originally posted by : Dr. MPS RAMANI Ph.D.[Tech.]

According to ancient Hindu practice inter-caste marriages were of 2 types. If father belonged to a higher caste and mother a lower caste it was called an anuloma marriage. If the father belonged to lower caste and the mother to a higher caste it was called a pratiloma marriage. Under anuloma the child belonged to mother's caste not fathers caste. Some 50 years back the Namboothiri Brahmins of Keralam used to marry Nair women of lower caste. Their children were considered to be Nairs, the mother's caste. In Pratiloma marriage the child belonged to a caste lower than that of father.  Yayati was Kshatriya and he married Devayani a Brahmin. Their son was Yadu. He was not a Kshatrya. The descendants of Yadu are called Yadavas.  Yadavas are OBC eligible for reservation. I have stated only what is in scriptttures, not my personal opinion.

please advise on the basis of DOPT insturctions.