You cannot have two different surnames, you can have first name + surname/last name or first, middle and last name. Since you are discussing insurance, property etc. It would be very important to stick to one surname.
A name change can be done for all the documents. For the sake of simplicity, I would say change the voter ID document because the rest of your marks sheets, job records, Aadhaar, caste, and PAN have the same surname.
First discuss with your family, what you caste and sub-caste are and what benefits will be given for which surname. Then accordingly change the certificates.
Once you decide on the final name + surname, meet the Notary in your town/city who will help you to get a legally valid name change document. Once you get this, then publish the change of name in two newspapers, one English and then one Vernacular language.
Now you have legal proof of your new name. Then meet the local corporation officer/registrar of marriages.
Generally, for marriage registration, you will need SSLC marks card or passport, residence proof, marriage photograph/invitation card etc.
You will need to fill in a form and pay the pre-determined fees. The forms and procedure might vary slightly from state to state and from religion to religion.
For Hindus, in Karnataka, the form is like this (http://www.karnataka.gov.in/karigr/Downloads/Marriage%20Forms/hindu%20marriage%20forms.pdf).
Voter's ID name correction can be done online also. You need to visit the National voter's services portal and fill out the details for name correction in form 8
If you still have any queries please mention the different surname names and the documents that carry them and what surname you intend to keep now.