ITI stands for Industrial Training Centres wherein trianing in given in techincal fields so that the students can start look or employment or self employment in motor and machine related sectors. This two year course comes last in the line after a BE, B Tech in the engineering sector. Some people complete ITI and then take a lateral entry into a degree course.
It is obvious that you cannot get any knowledge without attending the classes. If for some reason you do not have time, money and are currently in part-time employment or employment based on your 12th education, you can always join an evening college or even distance education degree course and complete it. IGNOU is one the largest distance education university that has many study centers all over India, the fees are very reasonable and also you have a grace period to complete the degree.
IGNOU also has a ' VIEP' vertically integrated engineering programme (2-6 years), here student with only a 10th standard pass also can take up a diploma or degree course, complete, exit for employment and then re-join for higher studies of Mtech etc.
Please consider this instead of trying to be misled by illegal centres that can create fictitious attendance register and get you an ITI certificate. Even if you get one and join as an employee, your lack of knowledge and skills would stand out.