My friend is an alumnus of IET Lucknow and according to him, with a rank of 5915, it will be hard to get Chemical Engineering. In his year, only a few general category students received Chemical in the fifth round with a general rank greater than 6k.

However, because the scenario changes every year, there is no certainty that you will get it. Also, given HBTI's split from UPSEE, getting into IET with this rank appears to be extremely difficult. It's all a matter of luck. 

According to the cutoff trends in recent years, the required cutoff for the Chemical branch is 2856 for General Category.