it is clear from the question itself that it should be zira'at. any dictionary will tell you that zira'at زراعت = kheyti karna in the question it is asked: 'masjid banana ya kheyti karna' to which alahazrat has replied zira'at karna ==== besides, ziyarat cannot be used in this sentence thus: "qabron par masjid banana ya ziyarat waghayra karna haram" no one does "qabr par ziyarat" as in the sentence - it should be "qabr ki ziyarat". this and the fiqhi position of the imam concerning visiting graves (that it is permissible), and refutation of wahabi/devbandi opposition is well known.
In the different versions of Irfan e Shari'at, we see two different terms used. In the first question of Chapter 3 about praying Salah towards a grave, some editions use the term Ziyarat whilst others use Zira'at. In the old copy from Ridawi.org, Ziyarat is used: In the digitised edition from alahazrat.net, Ziyarat is used: I found a really old copy on Rekhta which uses Zira'at: In other books which reference and quote this passage, Zira'at is used. In 'Imam Ahmad Raza awr Radd e Bid'at o Munkirat': In 'Bid'at key Khilaf Saw Fatwey':