By doing so your first year which you have studied at nit arunanchal pradesh will go in vein and that year will be treated as a drop year and for your information drop year does not have any impact on jobs or going abroad for that matter but yes one should avoid it if one can and since you are in an nit that too chemical branch so you should avoid doing this just for the sake of getting cse as you can apply for branch change and secondly you can practice coding despite being in chemical branch and apply for off campus placements in case companies do not allow you otherwise final decision is yours