How defend against rooks in 7th rank? I find it hard to defend against rooks placed in 7th rank.
What are the possible defense options?
Please share your knowledge.

[FEN "r4rk1/p1pRR1pp/1p6/8/8/P6P/1P3PP1/6K1 w - - 0 1"]

1.Rxg7+ Kh8
2.Rxh7+ Kg8
3.Rdg7#
In general, prophylaxis can be used to prevent the rooks getting on the 7th. This is the preferred defense; common challenging moves are to contest open columns with your own rooks, or to guard the 7th rank squares with your minor pieces.

In the case that the rooks are already on the 7th, you should secure the most urgent threats (where your king is or where most of your loose material is), and then trade off rooks or go on the offensive.

Hope that helps!