HI,

You've scored relaively good marks. You can expect your name is either second or third cutoff for the course of MSc Plant Biotechnology, because as of now the first cutoff list is released by DU in which the cutoof for ST category has gone 205. So, usually it comes down till third fourth cutoff. Just be patient and wait for the cutoff lists.

Your chances in MSc zoology are not that good as the cutoff for your category is around 231. You can expect it to go down but till the cutoff will reach around your score..there might not be seats left. But hope for the best. there is still chance that you might get into this.

And the answer to your last question, yes it is important to do your Masters from a reputed college or university. As it displays your hard work, skill and if you're pursuing masters from a reputed college then you get a hell lot of more opportunities as comapred to a low-grade college.