In JNTUH you can drop a total of 8 credits according to the R13 regulation. But, you cannot risk dropping any Practical subjects.
Theoretical subjects in 1st year carry 6 credits while from 2nd to 4th year, they carry 4 credits. Basically, you can drop any two theoretical subjects from 2nd to 4th year as the credits sum up to 8 credits.
Otherwise, you can drop only one theoretical subject from 1st year as it is 6 credits only. The remaining 2 credits from 8 credits are of no use.
Moreover, you cannot drop technical seminars, mini projects, major projects, and comprehensive viva. Further, the JNTUH automatically drops the two lowest scored subjects.
I would advise you to study hard from the first year itself and don’t rely on anything else. Hard work always gets paid off.