It is obligatory to do Hajj immediately; once a person is able and has the means to do Hajj, he must hasten to do it, and it is not permissible for him to delay it. This is the view of the majority of scholars.
See the answer to question no. 41702
In the answer to question no. 132011 we stated that giving up an opportunity to someone else with regard to acts of worship is of two types:
1.In the case of an obligatory act of worship, it is not permissible to give precedence to someone else with regard to it
2.In the case of a recommended (mustahabb) act of worship, it is more appropriate not to give precedence to someone else, but if there is an interest or purpose to be served by doing that, then there is nothing wrong with it.
As you have not previously done the obligatory Hajj, and Allah has made it easy for you this year to have your name drawn in the Hajj lottery, then what you must do is perform Hajj on your own behalf, because the obligatory Hajj is one of the obligatory duties and pillars of Islam, and it is obligatory upon the one who is able to do it. The means of being able to do it have become available to you, so you must fulfil this obligatory duty towards Allah, may He be exalted, and it is not permissible for you to give precedence to your father in the lottery, because giving precedence to someone else with regard to obligatory acts of worship is not permissible, as stated above.
You have to speak to your father gently and apologise, and explain to him the Islamic rulings on this matter.
Performing this important pillar of Islam takes precedence over honouring one’s parents if there is a conflict between the two, and that does not come under the heading of disobedience to parents; you can honour your father in other ways.
But if you go against that and you give your father precedence over yourself, and he goes for Hajj instead, then his Hajj is valid, but you must hasten to perform Hajj as soon as you are able to.
The scholars of the Standing Committee were asked: is it permissible for a person to send his parents for Hajj before he goes for Hajj himself?
They replied: Hajj is obligatory for every free, adult Muslim of sound mind who is able to perform it, once in a lifetime. Honouring one’s parents and helping them to do the obligatory duty is something that is prescribed to the extent that one is able. However you have to do Hajj for yourself first, then you can help your parents, if it was not possible for all of you to do Hajj together. But if you give your parents precedence over yourself, their Hajj is valid. And Allah is the source of strength.
End quote from Fataawa al-Lajnah ad-Daa’imah (11/70-71)
And Allah knows best.