I had considered this as a possibility but felt that there was strong historical evidence that this was during the liberation of Budapest from the Nazis in late 1944/early 1945. The Soviets carried out this operation with a force of over 1 million men. The location of the building pictured above was right beside Vienna Gate in the Castle Hill precinct on the heights above the Danube and it was here (and in the nearby Gellert Hill Citadel) that there was very heavy and prolonged fighting during Budapest's liberation from the Nazis, which was what made me believe this was the more likely explanation than during the 1956 uprising. The city suffered a siege of approximately 2 months in December 1944-Februrary 1945 with much of it centred on Buda, and this siege is reported to have been one of the bloodiest of WW2. The Castle Hill precinct near where this building was located finally fell to Soviet forces only after violent battles in February 1945 shortly before battle's conclusion. The Vienna Gate, located not very many meters away, was one of the few entrances to that precinct and would have almost certainly been how the Soviets finally entered the precinct.The bullet holes are more likely to be circa 1956...
Edit: go to magnum website and select Budapest 1956 and see the work of Erich Lessing. Great work.