Before going into the facts of your case, we must see the Definition of Family in Law:
"Family" shall include the following relations of the deceased Government servant:
(i) Wife or husband;
(ii) Sons/adopted sons;
(iii) Unmarried daughters, unmarried adopted daughters, widowed daughters and widowed daughters-in-law;
(iv) Unmarried brothers, unmarried sisters and widowed mother dependent on the deceased Government servant, if the deceased Government servant was unmarried;
(v) aforementioned relations of such missing Government servant who has been declared as "dead" by the competent Court;
Provided that if a person belonging to any of the above mentioned relations of the deceased Government servant is not available or is found to be physically and mentally unfit and thus ineligible for employment in Government service, then only in such situation the word "family" shall also include the grandsons and the unmarried granddaughters of the deceased Government servant dependent on him."
Since you are an unmarried brother of your unmarried elder brother....You are eligible in accordance with clause (iv) of aforementioned definition.