Exemption s was mentioned under incorrect sections. Received U/s 143.1.a with deduction 0

Yes, revise the return with proper sections; as and when compliance window open, disagree to the demands.

sir why was my 80u not considered? do i have to file it in 80dd like i did it in previous years?

Following kinds of disabilities as certified by a medical authority qualify for tax deduction u/s 80U.

• Blindness
• Low vision
• Leprosy-cured
• Hearing impairment
• Loco motor disability
• Mental retardation
• Mental illness
• Autism
• Cerebral palsy

So, section 80U deduction applicable in your case subject to fulfilment of the conditions.

For more details refer: section-80u-income-tax-benefit-for-a-person-with-disability/

Section 80DD is for disabled dependent.   Not applicable in your case.

sir do i have to submit proof if i choose to disagree the demands

Yes. if opted for.......... But try for disagreement without that, if you don't have proof handy.

sir i have filed just as in my form 16. i have selected incorrect sections only. can i revise my returns now. i havent received any compliance in IT profile . A part of thd notice i received says "You are herewith afforded an opportunity to respond to the below mentioned adjustment(s) proposed u/s. 143(1)(a) within a period
of 30 days (thirty days) from the date of issue of this communication. Please provide the required information or file a revised return,
as applicable, through online mode. To submit response, kindly log on to www.incometaxindiaefiling.gov.in with your "user name and
password" and choose "e-Assessment/Proceeding" under the “e-proceeding" section.

can i revise my returns now?

You better file revised return u/s. 139(5)............

But the details of the notice will be uploaded in the 'e-processing' section after 3/4 days..... which you may reply accordingly.