Welcome to HCM,
You can have safe sex
after 6-8 weeks of CS.
But before that you have to consult your Obst and see about scar is healed properly or any tendernss is there or not,any vaginal bleeding from uterus
After observing all points you may go for sex.
Initially make your wife feel comfortable position so that un necessary pressure on her abdomen should not have.
Ok and bye.