Section 113(6)(b) in Rajasthan Registration Rules, 1955
(b)The executant's left hand should be taken and the ball of the thumb, after being wiped, should be laid on the inked plate and rolled from side to side (not rubbed) and pressed gently, but firmly with the operators own hand until sufficiently inked, and the inked finger should then be placed and lightly and carefully rolled on the paper on which the print is to be taken, in such a way that the pattern of the whole ball of the thumb, from side to side, is clearly impressed on it. It must be specially borne in mind that any reverse movement, either at the time of applying or removing the thumb, will cause a smudge and spoil the impression.