Parsing OIDs in CertificatePolicies from CSR object in CX509CertificateRequestPkcs10 in c#

Question

I am trying to parse a CSR, CX509CertificateRequestPkcs10 object to read the OIDs in the Certificate policies in extension but I am not able get to it.

CX509CertificateRequestPkcs10 request = new CX509CertificateRequestPkcs10();
request.InitializeDecode(csr, EncodingType.XCN_CRYPT_STRING_BASE64_ANY);
request.X509Extensions;
var certPolicies = (CCertificatePolicies)(extensions[iter]);
AsnEncodedData asndata = new AsnEncodedData(certificatePolicyExtn.Oid, 
certificatePolicyExtn.RawData);
List<string> data = new List<string>(asndata.Format(true).Split('\n'));
var CertPoliciesList = data.Where(x => x.Contains(AkOidFriendlyName)).ToList();