You have to submit a joint application to marriage registrar along required documents like proof of birth etc.
After scrutiny of your application, marriage registrar will send the notice to both the families for their information and to submit their objection for hearing if any before approval of the same. These processes normally take minimum 2 months.
The process will also expedite with physical confirmation from both the family no objection.
And if you have got already married and want to register only then you need to produce proof of marriage like marriage invitation card, witness, priest etc.
All the best