For ex, a file contain contents:
10.45.56.84 raj 10.49.31.81 mum 10.49.31.86 mum 10.81.51.92 guj 10.45.56.116 raj 10.45.56.84 raj
I want to
This might work for you (GNU sed):
sed -r '/10\.(45\.56\.84|81\.51\.92)/d' file