First of all, the example has some significant errors which should be corrected before we try to build on it.
Ram read story books during his childhood. Ram preferred reading story books when he was a kid. He became an adolescent and read story books. Now he is a teenager and still continues to read.
You should write "story books" instead of "story book" because presumably Ram read more than one. And if he had read only one, an article would have been needed. In addition, the normal idiom is "from his childhood days", the singular is not used in this idiom. Moreover, "adolescence" is a period in a person's life; "an adolescent" is a person during that period.
Now for your example:
- Ram has read story books since he was a child.
- Ram has been reading story books since he was a child.
Both of these are grammatically correct. In some contexts, Form 1 would imply that the action has now finished. Form 2 implies that the action continues. But without additional context, the meaning of 1 and 2 is pretty much the same.
- Ram has read story books since he was a child, but he now prefers to play sports.
- Ram has been reading story books since he was a child, and he still reads avidly.
Sentences 3 and 4 make the distinction clearer.