GATE

No, you cannot appear for BCA after GATE.

If you feel like working for core companies and have a desire to work for a better organization rather than crawling in those MNCs, then drop a year and do preparation for GATE.

This is according to the GATE 2017, negative marking will be only for the multiple choice questions (MCQs). For 1-mark multiple choice questions, 1/3 mark will be deducted for a wrong answer. Likewise, for 2-mark multiple choice questions, 2/3 mark will be deducted for a wrong answer. There will be no negative marking for a wrong answer in numerical answer type questions.

Most institutes state minimum eligibility to be an undergraduate B.Tech degree in Chemical Engineering. - The Indian Institutes of Technology have the added eligibility criteria of a valid GATE score, which is only relaxed for those who have obtained their B.Tech from an IIT with a CGPA of more than 8.0/10 as well.
Note- Some institutes allow the equivalent forms of B.Tech in Chemical Engineering, such as a B.E. in the same field.
Regards.

Preparing for GATE is a good option. It all depends on your interest whether you are willing to pursue BE or B.Sc.

Hi,
Graduate Aptitude Test of Engineering is somehow necessary for core branches like mechanical, civil and electrical for PSUs or doing M.Tech from a better college.
You can give 2 attempts of it after doing Bachelors degree. Then on the basis of SSC, HSC, UG grades and GATE score you will get the rank. If you have got a good rank under 500 you can get a call from PSUs or else you should go for M.Tech.

Hi Wani,
How are you?
Well, Graduate Aptitude Test of Engineering is somehow necessary for core branches like mechanical, civil, electrical for PSUs or to pursue M.Tech from a good college.
You can give 2 attempts of it after doing your Bachelor's degree. Then, on the basis of SSC HSC UG grades and GATE score, you will get a rank. If you get a good rank under 500, you will get a call from PSUs or else you can go for M.Tech.
Thank you and keep asking!