Hello Amin,
Please come back to the forum with a more specific description of what your planned network topology is.
Example: what underlying L2 links will be there between/among the sites. Also, if possible, include details
on what devices you plan to use so we can asses the supported functionality and capabilities.
Last but not least please specify what expectations do you have from these VPNs: privacy/integrity or just isolation among different traffic flow ?
Knowing the above would help members of the forum share their experience, views and suggestions.
Cheers
Istvan