All that is required for a valid will is signature by the testator and the signatures by two attesting witnesses. So yes, you can write your will on a piece of paper and get two witnesses to attest it, and it would be a valid will, provided that the bequests are legal.
In India, registration of Wills is not compulsory. A Will is not a compulsorily registerable document under section 17 of the Registration Act, 1908, (Act), and according to section 18 (e) it is the testatorÕs choice as to whether he wishes to register it.
A bequest is property given by will. Historically, the term bequest was used for personal property given by will and deviser for real property. Today, the two words are used interchangeably.
According to section 17 of registration act 1908, any document other than the documents specified in sub-section (1A), not itself creating, declaring, assigning, limiting or extinguishing any right, title or interest of the value of one hundred rupees and upwards to or in immovable property, but merely creating a right to obtain another document which will, when executed, create, declare, assign, limit or extinguish any such right, title or interest;
Section 18e of registration act 1908, Documents of which registration is optional- wills.
Reference: section 17 and 18e of registration act 1908