Can I get into the CS branch in IET Lucknow with a general rank of 1,935, a GL rank of 219, and a BCGL rank of 43?

Your rank is good and you may get CS and IT branches. But getting another branch will be difficult for you at this rank. But you can get admission with this rank in any other government college. The closing rank for the first round at IET Lucknow is 15000 for the general category and 16000 for the spot round. 

The cut-off for the CSE branch at IET Lucknow is as follows:

You can try the CSE branch at KNIT or MMM. You can try for other branches and after the first year, you can opt for a branch changing option.