Where do shares are held in PIS?

I want to know where does shares are held in Portfolio Investment Scheme ?

How to convert your account to PIS in zerodha ? What happen to current holdings ?

PIS (Portfolio Investment Scheme) is scheme of RBI under which NRI’s can invest in Indian markets.

You can get PIS letter with the help of Bank where you hold NRE or NRO account.

The process to convert your existing Zerodha account to NIR account is explained here.

I know all this process but I want to know that even with PIS shares are hold in our cdsl demat account. Right ?

Yes, shares are held in your Demat account.