Can we do chasse in foxtrot like quickstep ?
Also can we do more than 4 steps(6-8 steps) before turning for foxtrot weave steps ?

You should make it clear that you are enquiring about the International Foxtrot.
If it is the International Style, you can do a Reverse Turn with no Heel Turn for the lady and taking the steps outside the man. Simular to a Quick Open Reverse in the Quickstep. You then take 2 4 or 6 or any even number, and finish with the normal Feather Finish.
Question 1. Yes they are now doing Chasses in the Foxtrot. A few years ago that was definitely a no no . You would have to watch your timing with this one .

And for American Style, the answer is definitely"yes." The Chasse is a part of several standard figures.

Thank you for your reply !

yeah thats great:)