SRM Institute of Science and Technology, Kattankulathur

No, it is not like that. SRM University is also one of the better universities to pursue computer science engineering. There are some other colleges like VIT, BITS Pilani, etc. which are better than SRM university as well.
If you don't get a top one then it is better to take SRM University.

Yes, it is a good choice to pursue B.Tech (engineering). The placements are really better at SRM University's main campus. So it is better to take admission here. The only thing is, the main campus alone is recommended in case of SRM University.

With that score, your rank will not be that good to get the main campus. You may get the other campuses with this score. Your rank will be around 30000-40000. This is just a prediction.

Your rank will be around 20000 so you may get the main campus of SRM University. You can easily get other campuses with this rank.
The branches at main campus may not be good for your rank. You may get chemical engineering, civil engineering, mechatronics, etc. but at the other campuses you can get all the courses.

Your scores are decent but it will be easier for me to help if I knew your rank in SRM JEE examination. I think your rank will be around 25000-35000. With this you may not get ECE branch at the main campus but you can get the other campuses with that rank.

Yes, you can get admission in Valliammai Engineering College with the cut off of 191.25 as the previous year's cut off marks for electronics and communication engineering was just 182.5.
For previous year's cut off marks refer:
http://cutoff.tnea.ac.in

You have good chances of getting admission at SRM University and its campuses. You can get all the campuses except the main campus as you have medium chances only for it.
You can get branches like civil, chemical, ECE, EEE, etc. so you may get the desired course but not the main campus with this rank.

As per your rank of 72928, your chances are very low or nil to get a seat at Ramapuram campus of SRM university. You also cannot get these courses as they are one among the widely preferred.
So you may try it in the counselling.

I think your rank will be around 40000-60000 or more as per your score in SRMJEE and this score is not enough to get a good branch or even admission into SRM University and its campuses. Maybe you can get the Delhi NCR campus.
Try in the counselling.

Yes, you can get the main campus of SRM University (KTR Chennai Campus). Your score is really good so your rank will be around 10000-13000. This will make you eligible to get a course in the main campus of SRM University.