Need to do the following steps:

01. Your Educational Certificate, Marriage Certificate should be attested by General Administration Department of your state, after that, attestation of Ministry of External Affairs-India (Preferably from New Delhi) and Qatar Embassy in India attestation is required.

02. After all this,the marriage certificate needs to be translated into arabic and should be attested by indian embassy in Qatar
03. The attested translated certificate should be attested by Ministry of External Affairs Qatar.

along with this documents the other documents, list which was given by our friend in the beginning is required to process.

Hope this will help u out