I want to make up the many missed prayers of Fajr and Zuhr at the some time if it permissible.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

You have to make up the missed prayers immediately and do not delay them until the time of the missed prayer comes again, do not delay making up Fajr prayer until the time of Fajr, and do not delay making up Zuhr prayer until Zuhr time, and so forth.

If someone misses a prayer he has to make it up immediately, except in a case where one is busy in gaining the most necessary provisions for him and his dependants.

We would like to draw your attention, may Allah help you, that not performing these prayers at their proper times without a reasonable excuse, is a major sin, and you have to repent from that.  A warning about this sin is given in the Words of Allah: {So woe unto those performers of Salât (prayers) (hypocrites), Who delay their Salât (prayer) from their stated fixed times, …}[107:4-5].

Allah knows best.