For engineering a candidate should lie between age of 17-21 years . Also you have to clear Jee entrance exam to qualify for engineering admission  , also a state entrance exam like for Maharashtra it is MHT CET .

Hi there Ajith! Hope you're having a great day.

I would like to know what were you main interests during the span of three years gap because it can affect college placements since comapnies when coming for college will ask why have joined college after a gap of three years. As for your latest query, yes you can take admission in any college on the condition that you have appeared for any state exam or JEE Mains for getting admission. 

Hope this helps. Thankyou.