its unwise to compare them. both of them were the best at their era...
bradman was best when a ODI match had 60 overs and 8 ball per over....no review system, no powerplay and the game was still very much primitive
sachin was and is best at the modern era of the game...
so to compare them fairly one wud need sachin to go back in time and play in bradmans era, face the same bowlers and conditions and also bradman to come to the future and face what sachins faced...