The phrase "turn in grave" means to be so upset or disturbed by something happening that it seems a person would react even after their death.

अपनी कब्र में करवट लेना (जीवित न रहते हुए भी किसी कारणवश परेशान होना)

English Usage: If he knew what they are doing with his company now, he would turn in his grave.

Hindi Usage: यदि उसे पता होता कि वे अब उसकी कंपनी के साथ क्या कर रहे हैं, तो वह अपनी कब्र में करवट लेता।