No, you are not eligible for GATE 2018 as it requires 4 years graduation course like B.E/B.Tech/ B.Sc etc. Also, you can check the complete Gate eligibility below -

Gate Eligibility 2018

Or you can also try for below provided courses once you complete B.Sc Electronics -

MCA

M.Sc in Electronics

MBA

M.Sc computers

So decide well.
Good Luck!!!!