Cindy, unfortunately, no this is not CA legal. Semi-auto rifles can not have a pistol grip or thumbhole stock. This would fall into one of those categories. budsgunshop.com/feeds/state_reg/california_restrictions.pdf

The gun is not CA compliant as sold by Bud's. The CA complaint version sold by WBT is modified to make it CA compliant. If you notice it says **Product in picture is California compliant and may not depict actual CA compliant parts** From WTB FAQ -- Question: How do you make my gun California Legal? Answer: For the most part, AR style rifles will come with magazine lock. Almost all other firearms will come “featureless” using some sort of “grip fin,” no flash hider, no collapsing or telescoping stock, and no forward grip. Contact us for more details per gun if you have any questions or concerns. We are always happy to discuss! ........... Most likely the gun sold by WTB comes with a magazine lock, which means the mag cannot be removed without disassembly of the firearm action. Or it may come with a grip fin, who knows? ...... AND ...... At this site, CA residence must add the CA Compliance Kit in the related products tab to cart before checkout. >>>> prkarms.com/zastava-m91-7-62x54r-4x24-posp-10rd

Hey Cindy no one who answered your question is a California resident, nor are we experts in CA compliance law. (James is in NC. Edward is in NJ, and I'm in Oregon)
The Zas M91 IS CALIFORNIA COMPLIANT
There is an online firearms retailer called "Wilde Built Tactical" they specialize in CA compliant firearms, they are a current FFL holder, and they are located in San Diego, most of what they sell is CA compliant, And they list this as CA legal.
https://wbtguns.com/sales-items/zastava-arms-m91-posp-4x24-rifle-scope-included-24-california-legal-7-62x54r/
Their mission statement
"Welcome To Wilde Built Tactical, LLC. We Are A Licensed FFL. Founded In 2011 And Operational In 2012, We Have Served California As A Go To Gun Store For Firearms And Tactical Equipment Not Found Anywhere Else. We Specialize In Providing Semi Auto Rifles That Are CA Compliant And Impossible To Find At Other Retailers. We Also Serve As A Well Priced Source For All Other Firearms Available To California Residents Including On Roster Pistols, Shotguns And Rifles Of All Types. We Strive To Provide Exceptional Customer Service, Honesty And Affordability"
Contact info
You Can Contact Using The Form Below, Email, Live Chat Or Phone.
PHONE: (619) 667-9453
FAX: (619)535-3995
EMAIL: SALES@WBTGUNS.COM
FFL Requests: FFL@WBTGUNS.COM

Cindy, no Ma'am, the Thumb hole stock is the restricting factor on this rifle. Details under Rifles here : budsgunshop.com/feeds/state_reg/california_restrictions.pdf --------- Cheers and stay safe! ------ CA compliant : budsgunshop.com/product_info.php/products_id/45626/savage+22599+10+ghost+rings+law+enforcement+bolt+762+nato%2f308+win+nato+20+10%2b1+ghost+rings