Railway ticket upgradation 2

In a most important move Indian Railway have started up gradation of reservation ticket in to higher class. That is expected not only to benefit passengers but also benefit the railways in terms of filling up vacant accommodation in various trains, to upgrade full fare paying passengers to the next higher class against the available vacant accommodation.

In this scheme I have observed one trouble, which I am elaborating here with an example:

Passenger Mr. X is traveling from Jammu to Mumbai in 3AC with confirm berth no. 32. Mr. X has traveled up to Delhi in that berth without any problems, but after trail arrival at New Delhi, Mr. Y reached and told to Mr. X, this my berth, I have confirmed ticket.

Mr. Y has confirmed ticket in Sleeper class but his ticket has been upgraded in 3AC berth no. 32 on which Mr. X is already traveling with confirm ticket.
How this can be possible?

Yes this is true because Mr. X confirm ticket has been also upgraded in 2AC berth no. 31 but he was not aware about it.
Now question arise if Mr. X have the confirm ticket for 3AC then who will inform for his confirm ticket up gradation. This is the responsibility of Indian railway or Mr. X.

If Mr. X have confirm ticket then he will not ask to railway for up gradation but after confirmation Indian Railway responsibility is to inform to Mr. X.