If you ordered Baltimore Oriole World Series tickets by mail and have yet to get a response, odds are the news is bad.

According to the Orioles, although the original postmark date for orders was Sept. 27, demand was such they were able to accommodate only order mailed on or before the 24th. All tickets were in the mail by late last week and should be delivered no later than today.

Orders not filed are being returned, but that process is somewhat slower. All orders postmarked Sept. 25, and even some postmarked Sept. 24, will be returned shortly.

A limited number of obstructed-view tickets still are available for Games 6 and 7 at the Memorial Stadium box office only. TV/RADIO

The ABC network, with Keith Jackson, Howard Cosell and Don Drysdale as announcers, will telecast the Series (locally on WJLA-TV-7, Washington, and WJZ-TV-13, Baltimore). The oriole network, with Chuck Thompson, also will have the games, on WMAR-TV-2. Vin Scully and Sparky Anderson will describe the action on CBS Radio outlets. HOW TO GET THERE By Car

There are several routes by which to reach Memorial Stadium from Washington by car. One of the simplest is to proceed northbound on I-95 until it changes into Russell Street. Take Russell to Pratt Street and make a right. From Pratt make a left on Calvert or Charles and make a right on 33rd Street to the stadium. By Bus

There will be no Metrobus service to the World Series because Baltimore lies outside the legal jurisdiction of the system. However, Metrobuses are available for charter service. Any group interested in charter service should call Metrobus.

Max Leiderman of Silver Spring is arranging bus service to all four Baltimore games. Buses will leave Beltway Plaza at 6:30 p.m. and will cost $4 per rider. Reservations must be made before 11 a.m. game day by calling 622-2550. By Train

Amtrak can get you to Baltimore in time for the games, but does not have service late enough to get you back. Amtrak train No. 60 departs Washington at 6:10 p.m., arriving in Baltimore at 6:57 p.m. Train No. 90 departs and arrives exactly one hour later. Metroliner No. 124 departs Washington at 6 p.m. and arrives Baltimore 6:45 p.m. The last service from Baltimore to Washington is train No. 177, departing 10:25, arriving in Washington at 11:10 p.m. Parking

You must arrive extremely early if you expect to park anywhere near the stadium. Oriole officials recommend if you are driving, leave as early as possible. Consider parking either at Lake Montebello north of the stadium or in the Morgan State campus parking lot. There are shuttle buses to the stadium from both locations. Consider public transportation if at all feasible.