I had completed Diploma in chemical engineering after 10th and want to do study abroad. It is possible?

Normally speaking, universities outside admit students after completion of 12 years or more of studies. Diploma definitely qualifies in this respect, since you would have completed 13 years of studies. However, there are many nuances and pitfalls. Hence, I would like to advise you that please go to

After scoring good marks in 12th is advisable. All the best for your bright future!

It is advisable to complete 10+2 level. Then afterwards, do Bachelor course abroad.