Engineering in Lucknow

You won't get IET Lucknow with this rank. All the best.

At this rank, I don't think you will get IET. There are only 60% chances that you'll get IET.

If it's about placement then you can go for CSE, you can choose any of the colleges mentioned above. Anywhere CS/IT students get easy placements.
If it's about location. Lucknow is much better than Sultanpur in all aspects.
IET-Lucknow has a better campus than KNIT. Well, finally it all depends on your interest. As you already passed out 12th and if you're from CBSE board, you have already studied computer in last two years (I know it's option, but then also )
If you want to go for government jobs, just go for civil engineering, if you want to work in private sector, go for CSE.

Your chances would be high but you must check the official website of the college.

With this rank, you surely have a decent chance to get the college though you may get it in last few rounds.
All the best.