Mrs. Elba Gomez del Rey de Kybal of Washington, D.C. and Buenos Aires, Argentina announces the engagement of her daughter, Cynthia Vera to Byron Alexander Grant, son of Mr. and Mrs. William R. Grant of Oyster Bay, Long Island and Boston, Mass. A June wedding is planned in Oyster Bay.

Miss Kybal's mother, until recently a resident of Potomac Falls, Md., is a director at the Organization of American States. Her father, the late Milic Kybal, was financial advisor to the Inter-American Development Bank. Mr. Grant's father, fromerly vice-chairman of Smith Barney, Harris, Upham and Company, is vice-chairman of the Endowment Management and Research Corporation in Boston.

The future bride, an alumna of St. Timothy's School (Md), was graduated cum laude from Georgetown Unicersity. Her finance was educated at the Portsmouth Abbey School (R.I.), and graduated from Trinity College (Ct.). Miss Kybal and Mr. Grant will take master's degrees from the Colgate Darden School of Business Administration at the UNiversity of Virginia in May.T(TABLE) iversity, Prague and a well-known historian, was an early supporter of the Czech movement initiated by Massaryk and Benes to form the first Czechoslovak Republic. Between 1920 and 1939 he served as an envoy of Czechoslovakia to Italy, Brasil, Argentina, Spain, Portugal, Mexico, and the Central Amercian Republics. Her late paternal grandmother, Ana Saenz, the famous painter, was recognized as the classical representative of the three leading Mexican painters--Diego de Rivera and Francisco de Goitia. In the early 1900's they were sent to Europe to finish their studies under the auspices of the Mexican government (END TABLE) CAPTION: (TABLE) Picture, no caption (END TABLE)