@sathishastin if you have experience in drafting but not 3d modeling the first thing you are going to have to do is become familiar with the new type of spatial thinking. What version of Inventor are you using?
Going through the tutorials on the home page will be your first steps.

There are many ways to go about designing this type of part. Best practice depends on the material and how it is going to be made. Whether this is made on a CNC, lathe, 3d print, or injection mold will drive how some of the parameters and tolerances are designed.
If you are just wanting to do a straight up reproduction with no design intent that's one thing, but if you follow the actual method of manufacturing through the design process that will be helpful in the long run.
For example, the slots on the circular end will most likely be the last operation performed, as that has the tightest tolerance, and will require a secondary operation depending on method of manufacture.
If you are going to dive right in and heed all training advice, you could start by creating a sketch, inserting your image, scaling to the right size, draw and dimension the side profile, extrude both ways at the width distance, clean up with extrusions to further define the shape. Here is an example:

Again, I would recommend going through the learning tutorials, watch youtube tutorial videos, read the help articles, buy a training manual book and really become familiar before you attempt this.
You will have more headaches trying to muscle through the design than just learning the basics first.
If you create a good attempt attach your file and forum users can inspect and comment further.
Hope that helps!
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