Yes you can bring your parents here in qatar and can go for umrah by road. Here is the procedure.

1. Bring them here on visit visa. Do medical test for them and extend the visa.

2.Before you apply for umrah visa from traveler agents for umrah you should have atleast one or two month qatari visa validity upon arival.

3.when you get the umrah visa get a re-entry stamp on your parents passports from qatar immigration as they have to enter again in qatar.

Umrah visa will open again on ist rabi ula awal inshaALLAH by saudi embassy.

Thats all what you need. Best of luck and pray for me also.