All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is permissible for you to perform Hajj Qiraan even if you have performed ‘Umrah during the months of Hajj while not having the intention for Hajj Tamattu'. The jurists stated that a person who performs ‘Umrah (during the months of Hajj) while having the intention for Hajj Tamattu' is permitted to perform Hajj Qiraan but he is obliged to offer two sacrifices (slaughter two sheep), one for Tamattu' and one for Qiraan.
Mawaahib Al-Jaleel authored by Al-Hattaab Al-Maaliki reads: “The reality of Tamattu' is that one assumes Ihraam for ‘Umrah, and once he has performed it, he goes out of the state of Ihraam during the months of Hajj and then he performs Hajj in that same year, even if he is performing Hajj Qiraan, like if he assumes the state of Ihraam for Hajj and ‘Umrah together after he had performed ‘Umrah, so in this case he performs Hajj Tamattu' and Qiraan altogether; the author of At-Tawdheeh wrote: “This is according to the agreement of the scholars (in the Maaliki School), but he is obliged to slaughter two sheep, one sheep for Tamattu' and one sheep for Qiraan. However, some Qarawiyyoon (from the Maaliki School of jurisprudence) said: “It is probable that he is only obliged to offer one sheep as, in the Sharee‘ah, the rule of overlapping two acts of worship is confirmed [i.e. having two intentions for one act of worship]. But the author of Ash-Shaamil said: “and he is obliged to offer two sacrifices according to the stated opinion (by Imaam Maalik )…” [End of quote]
Based on the above, you are permitted to perform Hajj Qiraan but you should slaughter two sheep, one sheep for Tamattu' and one for Qiraan.
Allaah Knows best.