There may not be any standard datasets available for your task. So you have to build one from scratch and then pre-process according to your needs. The best source are students. Students often send/post their class notes to their fellow batchmates or to the public. You can get it from them. To help you get started the below link(s) may help.

http://www.ankurgupta.net/gate-notes/

I think you can ask PRImA lab, University of Salford or try to find the dataset of ICDAR.

I don't know your applicationl but these two might be of interest to you:

http://www.caa.tuwien.ac.at/cvl/research/cvl-databases/icdar2013-handwritten-digit-and-digit-string-recognition-competition/

http://www.caa.tuwien.ac.at/cvl/research/cvl-databases/an-off-line-database-for-writer-retrieval-writer-identification-and-word-spotting/

Have a look at what is at the IAPR TC11 website: http://tc11.cvc.uab.es/datasets/type/

Also, look through ICDAR proceedings for competition papers and contact the relevant organisers for the datasets - they should all be freely available (a condition of ICDAR competitions).

http://www.fki.inf.unibe.ch/databases/iam-historical-document-database/washington-database

for english handwritten 

You may have a look at the following links:

There are handwritten datasets written in different scripts.

https://www.researchgate.net/publication/281268726_Dataset_and_ground_truth_for_handwritten_text_in_four_different_scripts_-_Kannada_part?ev=prf_pub

https://www.researchgate.net/publication/280981089_Dataset_and_ground_truth_for_handwritten_text_in_four_different_scripts?ev=prf_pub

https://www.researchgate.net/publication/281268597_Dataset_Dataset_and_ground_truth_for_handwritten_text_in_four_different_scripts_-_Persian_part?ev=prf_pub

https://www.researchgate.net/publication/261349835_ICDAR_2013_handwriting_segmentation_contest?ev=prf_pub

https://www.researchgate.net/publication/281268500_Dataset_and_ground_truth_for_handwritten_text_in_four_different_scripts_-_Oriya_part?ev=prf_pub

https://www.researchgate.net/publication/281268550_Dataset_and_ground_truth_for_handwritten_text_in_four_different_scripts_-_Bangla_part_httpswwwdropboxcomshnsrj53d0ma1ij0zAABCE6-_cv-Zc6knYV3SObsMadl0?ev=prf_pub

Conference Paper ICDAR 2013 handwriting segmentation contest

Research Dataset and ground truth for handwritten text in four differ...

Data Dataset and ground truth for handwritten text in four differ...

Data Dataset and ground truth for handwritten text in four differ...

Data Dataset: Dataset and ground truth for handwritten text in fo...

Data Dataset and ground truth for handwritten text in four differ...

kindly if any one can help me in getting ancient brahmi script dataset

You can find many datasets specially written in Indian scripts here

https://www.researchgate.net/profile/Alireza_Alaei/research

how can i find ancient Indian script data set preferably Brhami, Indus, Devanagari

I would encourage you to investigate the Transkribus ( https://transkribus.eu/Transkribus/ ) technology and community/projects. There were also a large number of handwriting and early print OCR/OLR papers presented at the recent #DATeCH2019 (papers: http://datech.digitisation.eu/programme/accepted-papers/ and posters (mine included): http://datech.digitisation.eu/programme/accepted-posters/) especially the conference's Best Paper on the OCR-D mission/research (slides: https://www.slideshare.net/cneudecker/ocrd-an-endtoend-open-source-ocr-framework-for-historical-printed-documents paper: not yet available publicly).

Much of the above are technologies rather than your targeted dataset. But since funding for technology development is often project-support driven, checking out these places will lead you to many and varied places that you may find not just data, but valuable Kindred Spirits. :D GLHF... This personal journey reflection will likely give you some encouragement to pursue your Quest: https://medium.com/factminers-musings/transkribus-magazines-5-e75070d5f00f