You do this through a process called negotiation.
In this, you state what you would like and what you are willing to do and they state what they would like and what they are willing to do. Each party then adjusts their position in order to see if there is a mutually satisfactory outcome (or deal); if there isn't then the parties go their separate ways.
It seems that they have stated their position:
they will place in the place which I want but want me to relocate to the Training place for first two months
And your position (which you have not communicated to them) is:
it would be difficult for me to relocate for 2 months as I will be getting married next month
As it stands, your Best Alternative to a Negotiated Agreement (BATNA) is:
- Take the job and disrupt your marriage
- Not take the job
You need to tell them what you are telling us and find out if what you are proposing is even possible for the company.
When you know all of their relevant information and they know all yours it may be that a deal can be reached.