Both TNAU and TANUVAS are relatively similar institutions because they are state-run universities. There is no major difference between the two universities in terms of their infrastructure and faculty members.

However, when compared on higher levels, then TNAU can be considered slightly better than TANUVAS, regardless of their resemblance in academic profiles. 

Having said that, it is always a better idea to try for other institutes like CFTRI, IIFPT, or NIFTEM for receiving better exposure, alongside a greater knowledge base.